I love the Thunderbolts, should they come back post-Secret Wars this would be my dream squad. I wanted a cast of misfit characters, all of whom are killers and have flirted with villainy. I also wanted a team that was mainly covert with four of the team being very stealthy.
Hyperion - Mark Milton - The 4023 alternate reality version of Exiles fame that briefly joined the Thunderbolts when coming to 616. He's pretty much Marvels version of Superman, super-powerful but also a megalomaniac. He's the "break glass in case of emergency" type guy.
Nightcrawler - Kurt Darkholme - This is AOA Nightcrawler, though it's assumed that he returned to the AOA universe I do not think it was shown on-panel. I like the idea that he hung around. This version of Kurt is hardcore, raised by his mother and was trained by the HAND, his teleportation is a useful team for the team.
Winter Soldier - Bucky Barnes - The leader of the team, after being tasked with killing aliens by Fury, Bucky has turned his eyes back to the Earth. He has such a ruthless undercurrent that I believe he could keep such a madcap team in their plac.
Red She Hulk - Betty Ross - Not a killer like the rest but Betty is still a badass. Though in the main continuity I believe she is de-powered, old hulkie resurfacing is not such a large step. Betty is the team muscle.
Black Panther - Shuri- T'Challa's little sis. I would have it that Wakanda has fallen post-Infinity and Shuri has been cast-out by a new republic. She has also reclaimed the Ebony Blade from the The Black Knight.
Scarlet Spider- Kaine- I love Kaine, the clone of Peter Parker. He's probably killed more then anyone on this list yet still has some of Peter in him. He is torn between being the killer he was and the good man he wishes to be.