I love Pokerstars:
1. It has the best software of all rooms, very stable, fast.
2. He has many Freerolls, including CardsChat.
3. There is a Great Variety of Games, Sit & Go, Tournaments, Cash, many types of
poker games.
4. You can Play for Play Money to learn how to play another type of poker than No Limit Holdem.
5, Player traffic is very good.
On my list it could come in second to 888Poker. Since it's stable, it has a lot of freerolls, it has good tournaments and satellites and it's nice to play there.