I've only ever really played the N64 version, and for me it would have to be Yoshi. His attacks are so weak and he can't jump for anything. There is one trick though where you can repeatedly throw eggs up at someone and they get caught in the cycle. You can manage doing about 50 points of damage this way, but is rather hard to do and very impractical if playing with other people.

I'm surprised no one has mentioned Jigglypuff on here, since anyone I know unanimously considers her to be the worst in that game. Personally I have a lot of fun with her, but I have to admit that if I'm seriously playing it's a pretty bad character.

Wow. Lot of people seem to think that Olimar sucks, but I've actually had to forbid my little brother from using him when we duel, because he's just too powerful for matches to be fun.
- Both great ranged and melee attacks
- Really wide reaching Smash-attacks.
I swear; it's dam near impossible to get close enough to hit him and if you try to range he just quickly closes the distance. Of course on the downside Olimar quickly loses his Pikmin's, but it's quick to get them back.

As for me the obvious choice would be Pichu but that's too obvious so I'll settle between these two

Mewtwo: I never truly got the grasp of him. When you try to dodge he just slides all over the arena. On the upside he has good throws but that's pretty much it.
King Dedede: I know that he probably could be a good character but I hate him mostly because of his Up+B. If you're jumping straight up you lost your momentum at the top and fall down. If you move sideways you most likely hit him on something and then fall down. Besides of that it's slow and easy to defend against. I swear that "saving move" is even more contrived than that of Ness and Lucas's.

I would have to say olimar. He just doesn't have enough power behind his attacks. The only GOOD attacks he has are his pikmin, but its random which ones you get and it never helps me out. However, the pikmin has NO problem helping the person im facing out. They always get the best pikmin, ALWAYS get the final smash, and ALWAYS FREAKING KILL ME! I don't use olimar for that reason, and it's one of the reasons why I don't like to play ssbb as much anymore.

P.S.: I know that in ssb4 they made it so only 3 pikmin follow olimar and that it's now a set order, but this was posted BEFORE ssb4 was ever released. And I didn't go to E3 soooo........yeah.