Budokai Tenkaichi is a special exception, in that it's not so much a "fighting game" as it is a simulation of the DBZ fighing style (minus about three hours of screaming).
I suppose in the purely technical sense, it's a fighting game, but in terms of feeling like a fighter, it doesn't really pass muster. That's what the straight Budokai series is for.
Overall, I'd say that BT is a resounding success as an anime game because it's not a reskinned fighter, but a game designed to make the player feel like they're part of the show's famous battles. Budokai, however, is more like a fighting game that people put Dragonball characters in, which is less of a win in my eyes. I doubt anyone considers Soul Calibur 4 a Star Wars game, for instance.
I guess my thoughts on games based on existing IPs are that they should make me feel like I'm in that world. Spiderman should make me feel like Spiderman, Batman should make me feel like Batman, DBZ should make me feel like Goku, etc. A lot of licensed games suffer from being reskins of other, less good, games which only sell because they have a pop culture icon on the box. We should cheer on games like BT and Spiderman 2 for breaking that mold.
- J