I use to love TalkCity when you could use IRC to go to their chat rooms (they removed this but never really explained why - I did get an e-mail from them that they were adding this feature back but I have not had a chance to go back and see). The main problem is that they grew extremely fast and their servers could not handle all the new people and they became extremely slow. Imagine being in a great chat with someone and everything slows down so much that you might as well be sending e-mails back and forth and that was what it was like.
I like chat rooms because they are fast and TalkCity just was not realistically fast. If they add more servers and remove the horrible frames you are forced to use than they would have one of the best chat services available.