Well, lets see...
Lucas - Obviously, haven't had the chance to try his series. (Well, technically I could have tried the second game, but I never had an SNES, so that rendered it impossible in spite of the US release.)
King Dedede - I've played a few Kirby games, and they're fun enough, but I'm not a big fan.
Falco - Huge fan of Star Fox 64, lesser fan of Adventures and Command. Didn't like Assault, though.
For other characters I play frequently, Marth and Ike I'm a huge fan of the Fire Emblem series (and am eagerly awaiting word of when FEDS will finally be brought over to the US so I can finally play through Marth's story); Ness is in the same boat as Lucas; ZSS I liked the Metroid Prime series, but haven't been interested in the rest of it; Pit I never played his game; Lucario I'm only a mild fan of Pokèmon; and Sonic I mostly play specifically because I'm a huge fan of his series (though mostly the old games).
Honestly, there aren't many series represented in SSB that I can say I dislike (though there are several I've never played, and thus don't know if I'd like them or not). F-Zero, Yoshi, and Animal Crossing are the extent of it, and that last only has a stage, not a character. Although actually, I did main Captain Falcon in Smash 64 (couldn't stand the changes to him Melee, and it's even worse in Brawl, so I don't play him at all anymore), so I guess I used to main someone whose series I dislike.
Zevox