I'll use Ness when I feel like having a lot of fun, but if I get moody and upset, I'll use Jigglypuff and send whoever I'm fighting into a hissy fit about how small and fast she is. And then I play as DK, and they complain that he doesn't die, and that his punch is too good. Then I play as Peach, and they complain about Turnips. Then I go Samus, just to spam them with missles, then quit.
It's a vicious cycle, truly. Love it, though. : D