Ike, Ganondorf, Wolf, Captain Falcon.
luigi is horrible to play as to me
i cant kill s*** with sonic and that fat bastard...DDD! sonic is weak and DDD is just garbage
You know, now that I think about it, I'm worst with D3. I can't even chain grab with him (I know it's easy, but I never bothered practicing :P). He's my absolute worst. Every time I get him on random, it's an instant facepalm (which happened 3 times in a row once; same with Ganondorf -.-).
Oh, I take back sucking with Jiggs. REST KO WINNING THE MATCH FTW!
Ness, Lucas, Olimar, Ganadorf, Mario, Luigi, Wario, and especially Ice Climbers.
Also, pretty much any character that is hard to jump with. Jumping is my weakness.