To be a member of the Avengers, you have to be one of the best and brightest heroes in the Marvel Universe. It doesn't just require power, like Thor or the Hulk. Being an Avenger means being someone who sets the standard for what it means to be a hero, regardless of their abilities.
They are selfless and willing to lay everything on the line to save everything. It kind of makes you wonder how Hawkeye got in. While he is a skilled archer and has fought the good fight for a number of years, he can be a really big jerk sometimes.
10 Feuding with Captain America
There was a point that the Avengers consisted only of Captain America, Quicksilver, Scarlet Witch, and Hawkeye. In the beginning, the Avengers didn't get a lot of respect, as they didn't have an Asgardian or a rich guy in a cool suit of armor on the team; however, big victories over Doctor Doom and Kang the Conqueror changed that opinion.
What didn't change was Hawkeye second-guessing Captain America at every turn. He genuinely believed that he was better suited to lead the Avengers than Captain America. While Hawkeye eventually grew some respect for Cap, he still made those days more difficult than they needed to be.
9 Screwing Over USAgent
After the formation of the Avengers West Coast with Hawkeye as the leader, the government stepped in and put USAgent in charge. Not surprisingly, Hawkeye didn't take this too well, leaving the team and returning more than once. When Operation Galactic Storm hit, it was determined that only heroes with raw power could go on the mission.
Heroes lacking in such power, like Hawkeye, were left behind as a rearguard to protect Earth. Taking personal offense to this, Hawkeye got some Pym Particles from Hank Pym and became the size-changing hero Goliath, and, in the process, bumped USAgent off the team.
8 Switching Teams to Prove a Point
Hawkeye used to be notorious for having a chip on his shoulder about being a member of the Avengers, possibly due to feelings of inadequacy. He was surrounded by gods and super soldiers, after all. To prove a point that he could thrive on his own without powered surrounding him, Hawkeye decided to leave the Avengers.
So, to prove that he didn't need anyone to help him, he almost immediately joined the Defenders. It's easy to understand his need to break out on his own and establish his own name separate from the team, but joining another team isn't the best way to do that.
7 Judging Bucky
When Steve Rogers was assassinated after the superhero Civil War, Iron Man went looking for someone to replace him as Captain America. After several accidents with several well-meaning SHIELD agents, Iron Man finally brought in the recently resurrected Clint Barton, who wasn't wearing his Hawkeye gear at that point.
He offered Barton the opportunity to take on the shield and the costume. Barton refused and the mantle went to Bucky. Unable to let a situation pass without voicing his opinion, Hawkeye tracked the new Cap down to tell him that he was unimpressed.
6 Killing Mockingbird...Kind Of
During the 'Secret Invasion,' several heroes that were thought to be dead returned, apparently kidnapped and replaced by the Skrulls. One of them was Hawkeye's ex-wife, Mockingbird. Hawkeye, then operating under the name Ronin, was overjoyed and immediately defended her from his fellow Avengers who were doubtful of the situation.
The plan was even more complex and those heroes turned out to be Skrulls, though the "heroes" weren't even aware of it. When "Mockingbird" was revealed to be a Skrull, Hawkeye almost immediately executed her, an extreme reaction in a situation that required a more measured response.
5 Abusing Jarvis
Of all the side characters in the world of the Avengers, Jarvis holds a special place among them. Their steadfast and loyal butler, Jarvis played important roles in many of their adventures, even if it's just playing the part of friend and confidant. Despite this, Hawkeye wasn't always the nicest to him.
One moment saw him essentially ordering Jarvis in the most condescending way possible to clean and wax 50 bowstrings he had under his bed. This didn't sit well with Cap, Quicksilver, and Scarlet Witch, though even their admonishing glares didn't clue Hawkeye into his faux pas.
4 The War on Osborn
In the wake of the Skrulls' Secret Invasion, Norman Osborn was handed the reigns to SHIELD, The Initiative, and much of the security in the United States. Many of the former heroes that made up the Avengers found themselves on the run from Osborn.
Hawkeye, on the other hand, took his fight straight to Osborn in as many ways as possible, including jumping on live TV to make a lot of bold, revealing statements to the American public. Taking on Osborn is never a bad thing but Hawkeye made all of his moves without consulting his teammates or anyone else they impacted.
3 Making Things Awkward for Everyone
Hawkeye is not known for being a lonely guy. He has had relationships with a long list of Marvel heroes and villains, including Mockingbird, Spider-Woman, Black Widow, and Moonstone. The problem is these relationships overlap in timing, sometimes even when the various parties involved are on the same team.
This can make trying to run a superhero team super, extra awkward. But if there's one thing that Hawkeye knows how to do, it is making a situation way more awkward than it needs to be. It is not like everything is always his fault in this department, though it would be helpful if he tried to make better decisions.
2 Going Rogue
Once again, Hawkeye's obsession with Norman Osborn rears its ugly head and costs his friends dearly. This time, Hawkeye, in the guise of Ronin, decides to take his one-man fight to Osborn and sneaks into Stark Tower, which his target inherited when he took over SHIELD and the Avengers from Stark.
Even though he's able to take out many of the Dark Avengers, Hawkeye is inevitably captured, then tortured for the location of his secret base with the outlaw Avengers. Fortunately, Hawkeye's team gets out of their compromised safe house before Osborn's team arrives.
1 Killing Bruce Banner
This was a tough pill for Hawkeye to swallow. Even though it had been a long time since he had become the Hulk, Banner provided Hawkeye with a special arrow designed to kill him in case he did change and things got out of hand. A few months later, a vision from the Inhuman known as Ulysses Cain led the Avengers to believe Banner might transform and cause a huge amount of destruction.
When it appeared that Banner was responding to their questions poorly, Hawkeye shot Banner with the arrow and killed him. It proved to be one of the most controversial decisions Hawkeye ever made.