Path of Exile is a F2P Diablo style game worth checking out for those that do not wish to drop $60 for.. that other game. Path of Exile has a much more complex skill system with Millions of Possible combinations and a good deal of other changes to make it stand out from just being a Clone type game.
4 hours into the closed beta and it is also fairly difficult.
The difficulty has been ramped up since the patch on Wednesday(brutal in some cases even on normal) also the new int/dex class is becoming available for testing for the public weekend as well.
Sign up and download it...it's free and quite good particularly if you need a quick fix before D3