It is a rough tie between OpenRPG and Klooge. There are are a couple issues that would swing my opinion one way or the other. Much depends on the system played though.
For d20 games Klooge has it hands down. For my Riddle of Steel games (which is my preferred system) OpenRPG provides the dice...
As an owner of OpenRPG, Klooge, and Fantasy Grounds let me try to give my opinions of each. Let me start off with the fact that I play your standard d20 fare which is supported by all these but my real pleasure is in The Riddle of Steel which is not as easy to use in some of these programs. I...