Well I have played most of the DBZ games that have come out.
My fav is Budokai 3, while I have played Tenkaichi 1.
I just did not like the feel or look of the game.
I hated the camera angle, I would have preferred that they kept the camera like in Budokai 3.* side view*
I have yet to play the second one but I heard that it is very good.