8. Captain America - The Winter Soldier
Ed Brubaker's time on Captain America is probably Cap's best known run, and rightly so. The series is famous for reviving Steve Roger's sidekick Bucky Barnes, not as the silly hero of the past, but rather the Winter Soldier.
As a villain who worked under the Soviet Union, the Winter Soldier was one of Cap's greatest enemies until he was eventually brought to the good side. It's a shame, as it meant that he lost one of his few foes that wasn't either a thinly veiled reference to Nazism or a straight-up Nazi. Subtlety has never been Marvel's strong suit.
Furthermore, the series focusing on the resurrection of the Winter Soldier has been hugely influential on the cinematic universe. While the comic bears almost no resemblance to the film of the same name aside from a couple characters, both had vast changes for Captain America. The events of the Winter Soldier is still being felt in the cinematic universe, and will likely continue to fuel a lot of conflict, even if Black Panther agrees to not kill Bucky for now.