The characters I have left that I'd like are Dante (Capcom), Agumon (Bandai Namco), and Crash (Activision). Perhaps also Tracer (Blizzard, not sure if it would fall under Activision Blizzard with Crash). If we could get multiple characters from companies, Sora or Geno (Square Enix) and Master Chief (Microsoft, mainly for the moment in gaming, not necessarily for the character). And if assist trophies could become characters, Bomberman (Konami). On the Nintendo side, Dixie Kong, Bandana Waddle Dee, and Isaac.
I actually think after Banjo & Kazooie, we're not going to get big shockers. I think if Square can get another rep, the last character could be Sora or Geno, which I think would be a fitting end to the pass. If not, Crash I think has the most potential to "top" what we've had so far.
Those are the characters I've considered the most, and I'm certain one or both characters will be ones I haven't thought about, or haven't considered deeply. I'm content with the roster as it is now, and getting every character regardless, but those are the characters still on my mind, at the moment.