Haven't played a game there in a while, but I like Carbon the best.
Stars is fully functional but boring.
These days I am liking the BetOnline/SportsBetting interface. especially for ring games. Almost evertyhing you could want to know is on the page the table is on. Very little need to go back to the lobby.
WPN (AmericasCardroom/Blackchip) works well enough.
ALL sites seem to prefer little teenie weenie type fonts for chat. And around here we like to chat.