After reading through the thread, I have to agree with a bunch of them. 
Best: Zabuza, he kick major @$$, but Spike's death was good too.  Yeah, you knew it was coming but it fit the series. 
Funniest: Kakizaki.  I love watching Max's head turn as the missle goes flying by to hit Kakizaki's valk. 
Worst death because I was pissed about it: Hughes from FMA.  He was my favorite supporting character!!!  I think they did a good job since you actually CARED that he died and wasn't there specifically to be killed. 
Hey, Max, why is the Uchiha clan deaths funniest?!?!