PartyPoker

The only poker site i've ever played for real cash on is PartyPoker.

I'm just wondering if anyone else ever plays on it?
I've never seen anyone speak about it, is it a bad idea to play here?

There's a fair bit of discussion of it. It's got loose players relative to most sites. Some like that for the bad plays, some don't like the suck-outs and swings that playing against such loose players entails.
Overall, though, it's one of the more long-standing sites and is worth playing at, although it's worth looking at other sites (hint - the links at the top of the forum) if only to take advantage of more sign-up bonuses (which can help boost a bankroll nicely, especially if you're around a break-even player and don't get to boost it much otherwise)