Pocky-Yoshi- No one, LOL! The main reason I dislike so many of the others is the fact that they make way too much noise. Stupid reason, I know, but it's annoying. I think the top most annoying character where a lot of pointless noise-making is concerned would be Talim. I really, really don't like fighting against her--not because she's a challenge, but because she's just annoying. Raphael doesn't make a whole lot of noise and what noises he does make sound like snarls and growls, neither embarrassing or annoying in my opinion. ;)
Senzait- Thanks. Yoshimitsu is funny, I'll admit. His noises are more comical than they are annoying. I like fighting against him, but I can't see myself playing as him. He's way too...silly, LOL! Honestly, he reminds me of Clopin from Disney's Hunchback of Notre Dame. XD
It seems like lagging is the big issue with online gaming (from what I've heard anyway). It's a lot of fun to get some buddies together (offline) and just take turns beating the snot out of each other. Did that for 5 hours straight the other night, haha!