My site promotes RakeBreak, but if you want rakeback then its worth checking out multiple rakeback sites as while most have sites like InterPoker, some have additional offers that stand out.
PokerSourceOnline are mainly good for US players.
I'd recommend looking at what sites are most profitable to play at - you can't get rakeback for Party, and some of the sites are tougher or have mire limited games available... a good rakeback offer can help a site to be worth playing at (and can support a very tught style of play in particular), but it shouldn't be the only reason for choosing a site. All the sites CC promotes have reasons to play at them just for the available games.