If ever there was a character who deserved better than the treatment he got in X-Men: The Last Stand, it's Juggernaut. Professor Xavier's half brother was so totally stripped of his personality and motivation that Vinnie Jones was brought in for the role without anybody batting an eyelid. He was nearly redeemed in DOFP, but his part was replaced with Quicksilver instead. It wouldn't be hard to do Juggernaut right, just introduce him as a mercenary thug for one sequence, cast the part with an actual actor (or at east someone who knows they're being paid by the muscle) and maybe throw in a mention of estranged family and everyone would be happy.