For a guy like me that really doesn't like super hard core fighters I've enjoyed all the current gen DBZ games. Each one had it's own little problems, like the second one's story suck big time, the third game was cheap and left to much up to random guessing. But all in all I've had fun playing them all.
P.S. the fourth one, Budokai Tenkaichi, is not a fighter but more in the vein of a one-on-one beat 'em up. Pretty fun and really fast paced