The 21st century has been in many ways the century of Marvel, dominated by the MCU. The live-action franchise is heavily influenced by a number of great Marvel Comics runs during this era, including a number of Avengers single issues that have inspired the movies and TV shows and continue to do so.
After the '90s, which saw sales plummet for all comic books, the early 2000s marked a return to prominence for the Avengers and related titles. Some of the most consequential - and popular - events in Marvel Comics history happened in this period, including House Of M, which continues to loom large for both the Avengers and X-Men.
10 Dark Avengers #1
Dark Avengers #1, written by Brian Michael Bendis and drawn by Michael Deodato Jr., is a major issue from 2009 that takes the Avengers to a place they've never really been before. With Norman Osborn now the head of National Security, he puts together a Dark Avengers team that are mostly villains, including Mac Gargan as Spider-Man and a powerful version of Captain Marvel.
It's a great issue for inverting the premise of the Avengers, and also for potential clues to the future of the MCU. A Dark Avengers team could be brewing as The Contessa collects potential recruits like U.S. Agent and Yelena.
9 Black Panther #15
The marriage of Black Panther and Storm, one of the most monumental events in Marvel Comics history happens in Black Panther #15, making it an essential issue for the period. The marriage is key on a number of levels for Marvel fans, as it pays off a long-running storyline that tied the two together in their youth, as established in prior X-Men comics, and it also sets up the future.
Major conflicts arise between the X-Men and the Avengers in the years following this issue, pitting the newlyweds against each other in powerful and tragic ways.
8 World War Hulk #2
World War Hulk #2 is a fantastic issue for many reasons. One is the gargantuan scale of the battle between the enraged Hulk and his former allies on the Avengers. Another is the exploration of the consequences of the Avengers' previous actions.
The Illuminati, made up of many members of the Avengers, exiled Hulk off of Earth and he ended up on Sakaar. His experience there, including the death of his wife, leads him back home for revenge. The issue features great work by longtime comic book artist John Romita Jr, depicting the endless devastation.
7 Avengers #503
Avengers #503 is a major issue in a cataclysmic series of events that would lead to massive consequences for the Marvel Universe. This is the final part of the "Avengers Disassembled" storyline that sees the Scarlet Witch go on a rampage against her team after discovering that her memory has been altered to hide the truth about her children.
Written by Brian Michael Bendis, the architect of much of the Avengers comics of this era, it's a key moment in the transition to the modern era of Marvel. The nature of the Scarlet Witch's powers is also of enormous importance in the issue, as there is a debate here about whether they stem from chaos magic or not.
6 Young Avengers #1
The Scarlet Witch's children with The Vision have been a major thread in the comics going back to the '80s, and they've become one in the MCU. That makes Young Avengers #1 a key issue from the 2000s. Though it's not immediately obvious, the characters of Wiccan and Speed are eventually revealed to be Tommy and Billy Maximoff reincarnated.
The issue is also major for bringing together a number of characters who are all in the MCU at this point or are about to be, like Kate Bishop, Kid Loki, and America Chavez, making the Young Avengers a team the MCU is building to.
5 New Avengers #31
Several storylines from the 2000s have inspired MCU movies and shows, including Secret Invasion. New Avengers #31 is a key issue in that storyline for the shocking reveal that Spider-Woman had been a Skrull. This revelation kicks off a major conflict where the Skrulls begin an all-out invasion of Earth.
It's a great issue, written again by Bendis with art by Lenil Yu, that focuses on a battle between Doctor Strange, Wong, and The Hand. Also present is Echo, Maya Lopez, who will be appearing in the upcoming Hawkeye Disney+ series.
4 New Avengers: Illuminati
The Illuminati are likely to make an appearance in the MCU at some point, now that all of its major members are available for the franchise. New Avengers: Illuminati is a key one-shot issue from 2006 written by Brian Michael Bendis that establishes the concept and secret history of this clandestine organization.
Comic book readers discovered that Illuminati has been at work behind the scenes going back decades in Marvel continuity and was instrumental in exiling Hulk from Earth, which would have major consequences for many characters.
3 New Avengers #1
New Avengers #1 was a major issue in many regards. It's the first Avengers team book to feature both Spider-Man and Wolverine, instantly making it one of the best Avengers rosters ever. It also establishes a new era for the team after the "Avengers: Disassembled" storyline left Hawkeye dead and the team in ruins.
The great art by David Finch distinguishes the book, moving into the modern aesthetic that had also been emerging in the Ultimate Comics line. Writer Brian Michael Bendis guides the Avengers into a new era with this issue, which brings the Avengers back together when Electro knocks out the power in New York City.
2 Civil War #7
Few issues from the 2000s have been as influential on the MCU as Civil War #7. The iconic cover image of Captain America and Iron Man fighting found its way into the MCU, as did the basic premise of the story. The Avengers were split down the middle over the Superhero Registration Act, which pitted Steve Rogers and Tony Stark against each other.
The issue is an all-out battle between the opposing forces, with fantastic art by Steve McNiven that captures the brutal result of such powerful beings fighting each other in the streets of New York City.
1 House Of M #7
As influential as Civil War #7 was, there are few Marvel Comics that have had such a sustained impact as House Of M #7. Wanda Maximoff utters "No more mutants" in this 2006 issue, erasing all but a handful of mutants and setting off a series of events still playing out to this day.
Avengers Vs. X-Men, the Dawn Of X, and other storylines in the last fifteen years are all a consequence of this event in one way or another. This highly impactful story has also now influenced the MCU, with Wanda's power and her children coming to the forefront of the narrative in WandaVision.