Well, it kind of depends on how and where you want to play the game. The genetics are the same in both versions, but there are some differences that could be important to you. The PC version will allow multiple players to maintain separate games, while the Palm version only supports one player. The PC version has more features and improved graphics, but it's not as portable as the Palm version, which you can take with you and play just about anywhere. The Palm version also supports exchanging fishies with another Palm user who is playing Fish Tycoon, a feature that's not available in any other version.

I hope that helps you decide!