When I got into comics, Jubilee was Wolverine's sidekick and it was what it's still one my favorite times with Wolverine with the Weapon X thing, memory implants, conspiracies, and so on. That's the run that made me like Wolverine at the time, just because how unpredictable things could be with nothing being what it seems. I think Wolverine only regained my attention when he became headmaster recently.
Honestly, tho, I don't really care about who they decide to make next. There are people I want to play as, I guess, but there is no "they *should* make this character"; every character has its fanbase. They should be trying to make something to everyone; not everything to everyone, but every kind of people that is, for some reason, attracted to their game, should be represented by someone.