The Marvel Cinematic Universe has to be given credit for the near perfect casting choices made for each character. There's usually a lot of pressure when it comes to these things because, let's face it, comic book fans can occasionally get kind of crazy when it comes to mistakes involving their favorite comic book characters.  There's usually a considerable amount of doubt when casting decisions are announced and fans will either be met with a pleasant surprise or vindication for their skepticism.

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More often than not, the actors do their characters justice and the films of the Marvel Cinematic Universe are stronger for it. Some offer much stronger performances than others, however, so we're taking a look at the cast of The Avengers films and ranking them. We're going to take a look at several things, most importantly of which is whether or not we believed them as the characters. Ultimately, it doesn't matter how much effort they put in, when it comes to acting, all that really matters is whether the audience buys it. Keep in mind that we're judging these actors solely based on their performances in The Avengers, Avengers: Age of Ultron and Captain America: Civil War, since, let's be honest, that was pretty much "Avengers 2.5." Everyone in here gets an "A" for effort, but we're looking for more than that.

15 ELIZABETH OLSON AS SCARLET WITCH

Scarlet Witch in Age of Ultron

It's probably not the easiest thing to act like you can move objects with just a twitch or twirl of your hands and fingers, but Elizabeth Olson does a decent job of it as Scarlet Witch; at least initially. As strong as her performance is when we're first introduced to her in Avengers: Age of Ultron, it all comes crashing down when she starts speaking in that vaguely Eastern European accent.

If you're doing an accent, you have to do it well and she just can't seem to decide how to do hers. A minor slip can be forgiven, but her accent tends to come and go pretty frequently. We can understand that since Sokovia is a fictional country, and it may have been difficult to find a basis for her accent. But still, it would have been preferable for her to just pick an accent and stick to it. What we got really tainted her performance, despite her otherwise expressive (and impressive) active talents.

14 AARON TAYLOR-JOHNSON AS QUICKSILVER

Scarlet Witch isn't the only character that accent ruined, it also marred Aaron Taylor-Johnson's performance as the other twin, Quicksilver. The saving grace was that his accent is relatively consistent throughout Avengers: Age of Ultron so it doesn't affect the rest of his performance nearly as much.

Speaking of which, it wasn't particularly memorable, comparatively speaking. He plays Quicksilver as quite a fun guy but fails to really convey any real conviction in his anger against Tony Stark. A perfect example of this is the scene in which Quicksilver recounts the death of his parents to Ultron. You could interpret it as a brother putting on a strong face for his sister, but even if that's the case, we're seeing less of a strong face and more of a neutral expression with hints of disappointment, completely missing the mark.

13 JEREMY RENNER AS HAWKEYE

Hawkeye-Avengers

Hawkeye is a soldier. That much was clear when we saw him in The Avengers before he was turned into one of Loki's agents. He acted like a soldier and little more; no snarky comments, just the mission. Then Black Widow whacked him on the head and he was right as rain...almost. That's when we got to meet Hawkeye for real.

Renner's portrayal of Hawkeye is pretty consistent and it's believable that, as a regular soldier with exceptional aim and a ton of arrows, he'd have to stay focused to keep up with the rest with all their godlike powers. He's witty as hell, and when it matters, Renner is able to give Barton just the right amount of emotion. However, it's not enough to keep him from fading into the background. He doesn't have that kind of presence on screen and that has nothing to do with his character.

12 ANTHONY MACKIE AS FALCON

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You can tell that Anthony Mackie enjoys playing the Falcon in the MCU because he brings a real joy to the role. He's fun, confident and witty, which is why he's so entertaining to watch, especially when he's in a scene with Captain America. You can really buy it when they become instant friends.

Unfortunately, as entertaining as Mackie's performance is, it works on his charisma alone and when you look at it as a whole, it doesn't do anything for the character he's playing. Falcon is a former para-rescue airman who helped veterans in dealing with PTSD. That's huge for a character but it doesn't show at all in Mackie's performance. Instead, he almost comes across as being that one character who is just there for levity. That problem is still there even outside the Avengers films. Just look at the film that introduced him, Captain America: The Winter Soldier (directed by Joe and Anthony Russo) -- even there, he doesn't draw much from the character's background.

11 ANDY SERKIS AS ULYSSES KLAUE

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Let's get one thing straight before we dive into this character portrayal: Andy Serkis is an fantastic actor. Even in his brief appearance in Avengers: Age of Ultron, that's evident. His South African accent is pretty spot on and he wears the look and personality of a gruff, black-market arms dealer well. He plays Klaue as a man with a lot of experience dealing with all sorts of people, which becomes clear in the scene where he mocks Wanda and Pietro despite having seen their powers.

The few flaws in Serkis' performance can be boiled down to the brevity of his appearance. You can't give a character that much depth in such a short amount of time, though not for lack of trying, given the way Serkis subtly refers to the character's history by way of bringing attention to his tattoos or the expressions he chooses to give when mentioning Stark to Ultron.

10 CHRIS EVANS AS CAPTAIN AMERICA

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Next up on our list is Cap himself, the de facto leader of the Avengers. Evans plays the character well enough and we can believe that he's a soldier coming to terms with being thrown out of his era. It's because of the smaller things, like how happy he looks when he gets Fury's rather dated flying monkeys reference in The Avengers or when he gives us that subtle look of satisfaction when he looks at the Avengers facility and says, "I'm home."

Aside from those moments, however, he seems a little too bland. That's great when he's with the rest of the Avengers and his character can counter Stark's eccentric charisma, but when it's a scene focused on him, it can be a little dull. We're not saying that he's a boring character, not at all. In fact, the Captain America films give him plenty of moments to really shine, but when you have a large cast as you do in the Avengers films, it can sometimes feel like he's struggling to avoid fading into the background.

9 SAMUEL L. JACKSON AS NICK FURY

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It goes without saying that Samuel L. Jackson knows how to take command of a scene, which is why he's perfect for the role of Nick Fury, former director of S.H.I.E.L.D. He can act like a leader who's been through it all: the horrors of war, the pain of loss, the grunt work and command. You can see it when he has that little talk with Tony in Avengers: Age of Ultron when he shows how well he understands Tony's anxiety about the vision he had.

Jackson plays Fury as being a cold, slightly sardonic, brave character, and while it's pretty believable, he doesn't really show a lot of range. That being a hallmark of the character, it's not Jackson's fault, of course, but it does mean that we never really get to see him shine. The closest we've come in the MCU is those brief few scenes in Captain America: The Winter Soldier. Every other film has been hesitant to give him that much focus.

8 JAMES SPADER AS ULTRON

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Ultron is not your typical villainous robot and Spader's performance really sells that point. He brings an unexpected humanity to the character in more ways than one. His vocal performance alone balances a cold, mechanical being perfectly with calculating, human villainy. He seems almost empathetic toward Pietro and Wanda Maximoff while simultaneously being hateful toward the Avengers.

His motion capture performance also has to be praised, specifically for that very first scene in which the character is still getting accustomed to his new shell, moving as though he was a malevolent, eerie puppet like the ones he talks about in that fantastic speech. That and the few other speeches he makes help to make Ultron more interesting than perhaps the film itself allowed him to be, which speaks a lot to Spader's talents. There are few who could have made the character as chilling and yet philosophically relatable as Spader did.

7 PAUL BETTANY AS JARVIS/VISION

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We learned through behind the scenes info that Vision isn't the easiest character to play. It's not because of the character itself, more in the costume and design of him. The suit is tight and it gets pretty hot inside. According to Bettany, there are cooling tubes running throughout the suit and he cannot hear very well. None of that shows in his performance, which you have to give him credit for.

He also plays Vision as being quite an innocent character, but one whose knowledge is vast and unmatched. He's the most powerful entity on Earth and he knows it, but he also knows that he's new to this world and that he has a lot to learn about it. That kind of wisdom comes through in Bettany's performance and it makes Vision one of the more interesting characters to watch.

6 PAUL RUDD AS ANT MAN

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Ant Man is a difficult hero to take seriously in the film. He can't be dark like Iron Man and he can't be especially heroic like Captain America. Thankfully, Paul Rudd makes it work by balancing the dramatic and comedic sides of the character. He also doesn't make the mistake of taking the character too seriously, which is important because it keeps him grounded and more relatable to the audience.

Because of that, the fact that his powers aren't initially as astonishing as every other Avenger in Captain America: Civil War, we still love his appearance in the film and cheer when he turns into Giant Man and starts to give Iron Man's team a proper thrashing. It's not easy keeping up with Robert Downey Jr and Chris Evans, so in terms of scale, Paul Rudd doesn't try to, which works for him and the character really well.

5 CHRIS HEMSWORTH AS THOR

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What Chris Hemsworth does with Thor is interesting. It's not just that godlike physique that sells the character, it's his ability to perfectly balance the formality of Asgardian speech with the very modern style of humor. The Thor films were perhaps too full with it, but when it's just him beside the Avengers, it's perfect. Hemsworth helps to distinguish the character from other superhero depictions.

Chris Hemsworth's style and presence is pretty much what you'd want in your adaptation of a fictional superhero god. But minor slips in his accent and a few facial and vocal expressions that were just a touch too melodramatic keep Hemsworth's portrayal of Thor from being as believable as it could be. Thankfully, you'll notice quite a difference between the two Avengers films, as well as the more recent Thor: Ragnarok, which shows us that he's definitely getting better with each film.

4 SCARLETT JOHANSSON AS BLACK WIDOW

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We simply can't imagine anyone else playing Natasha Romanoff. She leaps into any situation with confidence, regardless of whether or not she's facing aliens, gods or sentient robots bent on destroying humanity. That's pretty impressive, considering that she has no superpowers, but it's still believable somehow and that's thanks to Scarlett Johansson's choice to portray her as a highly-trained superspy with an unbreakable professional facade.

There are times when we see her begin to crack, though. For example, in Avengers: Age of Ultron, when she's talking to Banner about monsters. We see hints of a desire for a different life and it keeps the character from being one-dimensional, despite Johansson being compelled by the character to remain predominately unreadable and almost expressionless. You can see her change almost organically as the character grows familiar with her companions and begins to open up.

3 MARK RUFFALO AS THE HULK

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Anger, like pretty much all emotions, is more complex than it appears. It's not just yelling, fighting and causing some damage, it also involves a whole lot of suffering and internal strife. That's some heavy stuff and that's why the Hulk is such a great character. Mark Ruffalo plays Banner as someone who's dealing with anger as best he can and while it's not always blindingly apparent, you can see that it's there somewhere, bottled up.

But it's not just in his portrayal of Banner that we see Ruffalo's talent, it's in his motion capture performance as the Hulk. In his movements and expressions, you can see a lot of repressed rage spilling through. He grits his teeth, he pounds the ground and smashes everything in his way like an animal. He is a near perfect expression of anger in all its facets, but not so much that it completely hides the other side of the Hulk. He's just as tortured as Banner.

2 TOM HIDDLESTON AS LOKI

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A villain can't just be an evil entity bent on destroying everything, seemingly because they have nothing better to do. Their evil has to come from much more than sheer villainy, and Tom Hiddleston's Loki addresses that. Even if you haven't seen the Thor films, you'll still see there's more to Loki than meets the eye, thanks to brilliant (and often deceptive) emotive delivery by Hiddleston.

When he's first confronted by Thor in The Avengers, you see that he still cares for his brother and the life he left behind, he's still pained by it. Nothing else really matters, even in failure -- there's still that mask of confidence, as if everything is still going according to plan and you never really know if it is. He's the greatest illusionist in the MCU and we love him because of it. There are aspects of him we can sympathize with and aspects we have to resent and a huge part of that is because of how he is played.

1 ROBERT DOWNEY JR. AS TONY STARK

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We're not entirely sure if Robert Downey Jr. is even acting when it comes to his portrayal of Tony Stark. He's confident, charismatic and that all seems to come from a natural place. He can dominate a scene with his witty, sarcastic remarks, his use of space and the small improvised eccentricities.

All of it that is absolutely in-character and it's a testament to how well Robert Downey Jr. is able to draw from his own personality to create such a wonderfully complex character. Even in Stark's moments of anguish, it all seems to stem from more than just great acting. There's real anger and pain there, which is why the MCU's Tony Stark works so well. It's not just pretend, it's a character specifically built to accommodate the actor. What can we say? He is Iron Man.

Which of the Avengers cast stood out as the worst or best to you? Let us know in the comments!