It really comes down to what you are looking for. I think our
Top 5 Poker Sites list has a good collection of sites.
If you want traffic and never want to wait for a game,
Pokerstars or
Full Tilt Poker are the best 2 poker sites hands down.
If you want good tournaments, promotions for Canadians and looser competition check out a site like
Party Poker,
Betfair or
Sun Poker.
Not every site offers rakeback (ie. Party Poker, Pokerstars, Betfair, Sun Poker), but if you plan on playing a lot then definitely look into
one that does. We have an offer for
30% rakeback at Aced, which is on the Merge Network.