Royal Vegas lets you play on 2 rooms, Absolute Poker lets you play on 3 rooms, plus a tournament room. Paradise lets you play at a couple tables at a time, and they have a nice interface and lots of fish.
I recommend checking out the different sites on
www.idonk.com/poker.html that will give you all kinds of stuff for signing up for various poker rooms (free chips, amazon.com GCs, etc.).