I'm on Lucan D'Lere, as is my boyfriend, and we love the RP servers...I find that there's a good mix of RP and non-RP going on, which to me makes things interesting. Plus, the way we play, you can't always tell which we're doing, playing our char or just talking. There's a couple of people we talk about IRL stuff with, as well, but usually in /tell. Of course, no matter what server you're on, there's going to be all manner of inane chat across the zone in in /ooc and /shout, but hey, some of it's funny, the rest can be ignored.
Haven't tried out the other servers, Lucan's our choice.
-Pooka