I really like Absolute Poker for freerolls. Although you have to be quick at times, they can fill up pretty fast, or you'll be waiting around for an hour or so to play in a freeroll. But most of the players there are pretty nice. You get the usual jerk or two, but you aren't going to avoid all jerks anywhere. I play on Absolute almost every day. If you're really into freerolls, I suggest going there.