PokerStars is the main site I've been playing on since 2004. It has many great features, a large player database, and a great rewards program. It may not offer as many bonuses or a rakeback system as other smaller sites, but the difference is made up in the strength of the software. Technical support has always been great as well, with most questions answered within minutes.
PokerStars is a great site for new players as well, since it offers the lowest blind limits of any site. Anyone new to online play can easily deposit $50 and play penny tables without much concern of going broke. Currently PokerStars is offering a 100% bonus up to $50 for any new signups. A few hours of play are required to unlock the bonus, but it's relatively easy to obtain. Click the link below for further details.
Full Tilt has come a long way since it first opened several years ago. Lately it has become one of the best online poker clients with great software, a huge player database, and lots of celebrity pros frequenting the site. Some aspects of Full Tilt surpass PokerStars, while PokerStars is stronger in other areas. It really becomes a matter of preference when choosing which site to play on.
As for bonuses, Full Tilt currently offers a 100% bonus up to $600 for all new signups. This is substantially larger than that of PokerStars, however I wouldn't recommend this site for anyone playing below the 25nl levels. The lowest limit offered by Full Tilt is 10nl, which has a 10% rake instead of the 5% rake offered at every other limit. There's no reason for any new player to subject themself to playing with 10% rake, so avoid playing here until you have moved up the limits a bit.
