Recently, I've been playing and enjoying Valkyria Chronicles, Dragon Age: Origins, Odin Sphere, and Tekken Tag Tournament 2.
I would be very hard pressed to choose a "best" game, so I'm going to cheat a little and choose the most played game of the bunch. That game would probably be Tekken Tag Tournament 2.
I'm relatively new to the Tekken series and 3D fighting games in general, so naturally I have been spending plenty of time learning how to play TTT2. Right now, I feel comfortable with TTT2. I'm not great, but I can very safely say that I'm not awful. I know my characters, movement feels natural, and my general fighting game fundamentals have have helped in yielding decent results online. I'm improving, and it feels good. I keep coming back because I like seeing my efforts rewarded. TTT2 is an especially tough but satisfying game. I cannot help but keep playing it.