Captain America VI – James “Bucky” Barnes
For the longest time, “Bucky died in the accident that put Captain America in suspended animation” was one of the comic book truths that never seemed like it would change — until it did.
As it turns out, Barnes didn’t die in the Baron Zemo explosion either, suffering the same fate as Steve Rogers (and losing an arm in the process). Instead of being found by the Avengers, Bucky was thawed out by the Soviets, who did the only logical thing: they fitted him with a cyborg arm and brainwashed him to be an assassin. Barnes served for years as the Winter Soldier, eliminating targets for General Vasily Karpov and returning to the deep freeze between missions.
When Aleksander Lukin decided to use the Barnes in the present, he was eventually defeated by Rogers and regained his memories thanks to the Cosmic Cube. He initially tried to make amends by fighting on the side of the angels as Winter Soldier, but when Rogers was shot and believed to be dead, he reluctantly took over as Captain America. Sporting his own version of the classic outfit designed by Alex Ross, the former Bucky acquitted himself well, defeating the evil 1950s Cap and joining the Avengers for both the Secret Invasion and Siege events.
Even when Rogers returned from his journey through time, Barnes remained Captain America for a time. But when he was temporarily killed (I love comics) during Fear Itself, he returned to his Winter Soldier guise so he could pull off more secretive work. As shown in Original Sin, not all of his fellow heroes are convinced about Barnes’ intentions, but his run as Cap should have earned him some of the benefit of the doubt.