For me? I'll take a Bandai-Namco character. There's more interesting choices they have left to me. Capcom does have Dante and Morrigan Aensland, but nobody else does anything among notable characters(I like Power Stone, but it's even more obscure than Darkstalkers).
Bamco still has Digimon, Tales of, and Soul Calibur. I wouldn't mind having a Tekken character cause I never could get used to the system, so it'd be a cool surprise to try it in 2D alone. That is, where Sakurai makes an attempt to make them feel like themselves, not just throwing a quick moveset on to a character.
...Okay, not much more, but still more overall. Also, to clarify, I'm only listing series that interest me. If they aren't here, either they're somewhere in Smash or they don't interest me at all. Doesn't mean I dislike them or anything.