Even still, Marvel's The Avengers continues to be one of the favorite films among fans of the franchise. The MCU has grown significantly since six strangers banded together to stop one of their adopted brothers from invading Earth with an army of aliens. While the stakes have gotten larger over the years, it's important to respect the humble beginnings of the MCU.
Not only is the first Avengers film a huge milestone in the history of the MCU, but it is also a significant milestone in filmmaking. The Avengers was the first time a culmination film meant to connect every film that came before it was a massive global success. The resounding success prompted the MCU engine to kick into overdrive and never look back...except during time travel shenanigans.
7 It Was The First Time The Avengers Came Together
With so much history between the original six Avengers, it's nostalgic to go back and watch the first time they came together and re-hear all of the classic lines of dialogue. A lot of their interactions foreshadow later events and motivations while building the characters and relationships fans have come to know and love.
The first Avengers film did an excellent job of not only showing fans the team-building needed for six strangers to become a well-oiled machine but it also seamlessly mixed the major personalities and egos without anyone being pushed to the background. While the Avengers Initiative was first thought of in 1995, when the plan finally came to fruition in 2012, the dramatic success of the team set the tone for Phases 2, 3, and even beyond.
6 It Showcases The Vast Resources Of S.H.I.E.L.D.
The Strategic Homeland Intervention, Enforcement, and Logistics Division (S.H.I.E.L.D.) actually appears in Iron Man, Thor, Captain America: The First Avenger, and Iron Man 2 before showing up in The Avengers. Despite appearing in four previous films, they didn't reveal too much with respect to their knowledge, resources, and what they were truly capable of until 2012.
Before the Avengers came together, S.H.I.E.L.D. was seen as a shadowy government agency akin to the CIA or FBI. However, fans quickly learn that S.H.I.E.L.D. has nearly endless resources and financial backing when they are taken to the Project P.E.G.A.S.U.S. black site and again when the helicarrier lifts off from the water. S.H.I.E.L.D. truly flexed its muscles in The Avengers and its power was never taken lightly from then on.
5 It's The Film With The First Major Thanos Influence
The big bad of the Infinity Saga was the Mad Titan Thanos who made life more than difficult for the Avengers on several occasions. While Loki was deemed responsible for the Chituari invasion, it was actually Thanos pulling the strings from behind the scenes. Thanos loaned Loki the Chitauri army as well as the mystical scepter that contained the Mind Stone.
Thanos also ended up being the primary antagonist in both the third and fourth Avengers films making him responsible for three of the four threats that the collective Avengers have faced thus far. With the existence of time travel and the knowledge that Snapped people can be brought back, Thanos may even appear down the line as another serious threat or maybe even as an ally depending on the circumstances.
4 It Exposed The MCU To The Threat Of Space
While S.H.I.E.L.D. had some experience with aliens when Captain Marvel and Thor previously arrived on Earth, the Chitauri invasion was the first significant public alien presence in the MCU. The Avengers coming together to save the planet from an intergalactic threat really opened up the MCU to a larger universe for the first time, which allowed Marvel to rollout films like the Guardians of the Galaxy Vol. 1, Dr. Strange, and Ant-Man.
The space aspect was a big success in the first Avengers movie which resulted in Fiege and company traveling to the distant reaches of the universe as well as mysterious places such as the Quantum Realm, The Mirror Dimension, and even the Dark Dimension. Early hints of a multiverse were also dropped during Dr. Strange's first meeting with the Ancient One.
3 Rewatching With The Knowledge From Endgame Is Interesting
When rewatching The Avengers with the knowledge of what has happened since there are some differences due to some new information provided in Phase 4 properties. While there aren't any duplicate Avengers hiding in the first movie, it's interesting to see so many subtle blanks filled in such as Loki's impersonation of Cap after being apprehended, which actually varies between Endgame and Loki.
There are also other bits of knowledge filled in thanks to Endgame such as Hulk's hatred of stairs and Alexander Pierce attempting to confiscate the Tesseract from Thor after the final battle. Assuming Tony didn't have a mild heart attack in the main timeline, and knowing Loki didn't make off with the Cube in the main timeline, fans are curious to know how they convinced Pierce to let Thor take the Tesseract back to Asgard.
2 It's Coulson's Last Chronological MCU Appearance
While many fans continue to debate the canonicity of the pre-Disney+ Marvel television programs, the powers that be at Marvel Studios have heavily suggested that the only canon shows at this point in time are WandaVision, TFATWS, Loki, and somehow What If...?. With that in mind, the lovable Agent Phil Coulson is last seen, chronologically, in The Avengers.
Coulson did appear in Captain Marvel which premiered many years later but it takes place about 17 years before the events of the first Avengers film. Though with Coulson returning for a few episodes in What If...? - reminding fans of his hilariously quirky personality - perhaps Marvel is testing the waters for his return in a multiversal event.
1 It Cleverly Sets The Stage For Future Properties Such As Age Of Ultron, Civil War, Loki, & Even Black Widow
Going back to the original Avengers movie after having watched the properties that have come since provides fans with a lot more insight which translates to seeing more moments of foreshadowing and additional motivational influences for different characters. While Tony's PTSD is on full display during Iron Man 3, it stems from his trip to space which later drives him to develop Ultron which sets up the Avengers' second major team-up event. With the introduction of a successful, universe-hopping Ultron in What If...? perhaps the threat of the murderous A.I. is far from over.
Additionally, while Loki only escaped as a result of the Avengers' meddling in time, he was intercepted by the TVA in 2012 immediately following the Battle of New York albeit in a different timeline. The subtle differences between Endgame and Loki suggest that Loki might even take place in a third separate timeline, but Marvel has yet to speak on this. There were also several small hints dropped about Natasha's life in Avengers that finally came to fruition in Black Widow such as "Dreykov's daughter" and the infamous Budapest mission.
Finally, the Sokovia Accords of Civil War created a huge division among the team, and the fallout was much more devastating because of how close they had become in the years prior. While the Accords were a result of Wanda making a mistake in Lagos, that mistake was merely the straw that broke the camel's back. The camel of course being General Ross and the first straw of the pile being the Battle of New York.