Real time chess sites aren’t for me. Mostly because all that’s available is speed chess. Of course that’s because everybody is worried about engine users. Personally, I could never play speed chess very good so never developed a taste for it. As primarily a CC player, I need 3 days per move, not 3 seconds.
Still. on occasion I do play on Playchess as a guest. That’s because I own Fritz, so it’s free. My free trial membership expired a couple years ago, but since I don’t play that often and don’t care about a rating (during the trial membership my blitz rating was ~2000), like the appearance and ease of use, it’s the only place I ever play blitz when the mood strikes, which isn’t very often.
In any case here’s a brief summary of the more popular sites. If I didn’t have Fritz, I guess my first choice would be FICS.
The best interface. Same as Fritz and Chessbase programs. Watch GM games live even if your just a guest. When someone cheats it's displayed in the main chat room and their rating is deleted. Separate ratings for different time controls. 1 year membership. If you have any Fritz products you get a free temporary membership and when it expires, log in any time as a guest, but you get no chat or rating and are limited to the Beginners Room. Don’t worry about that though. There are a lot of guest players who aren’t beginners.
Many titled players at all hours. The ability connect to winboard makes it easy for members to cheat. It's interface confusing. I had a hard time figuring out how to play using it. When some guy, who seemed pretty nice, kept telling me how to reply to his chat messages, I still couldn’t figure it out.
Free site with similar style interface as ICC. You can use a selection of winboard style interfaces to play with. Cheating is a nuisance.
Saturated with cheaters. The chat rooms are porn or racial and religious debates. Play someplace else!.
World Chess Live
It has events, mostly tournaments and rare lectures. You have to download their software and pay membership dues. Associated with USCF. Not worth it
Chess.net only allows premium accounts to play there. Very few players and few events. $30 per year. Stay away.
Good for beginners. It has a fast registration process and a very easy flash based interface
Offers both real time and turn based. Worst site around. Free access is inundated with all kinds of annoying pop ups and the dues are ridiculously high…$10.00 per month. That’s a whopping $120 per year. Avoid it like the plague. A few years ago when I was just getting into server CC, I played a few games on this site and it wasn't too bad. Then somebody claiming to be GM Anir Bagheri got involved and eventually took over the site and turned it into a monster. I say claiming because this person popped up on a bunch of other sites and got thrown off all of them. I had personal correspondence with the alleged Mr. Bagheri when I was asked to be a moderator on the site shortly after he took over. It was my opinion that whomever the person was, it was not GM Amir Bagheri and I declined.