It's not just the best fighting game on the Wii, it's a great game regardless of which fighters you compare it to.
Fights are full of fast, flashy moves that are easy to execute thanks to the simple controls. The arenas have bright animated backgrounds that give way to anime-style power-up screens when someone is about to launch a special attack. These sequences look a lot like a cross between Street Fighter IV and Super Smash Brothers Brawl.
I have played the game with the Wii remote alone, and it has made me wish I had a better controller attached. Unfortunately my Wii Classic controller is in storage and my nunchucks are in a closet somewhere, so I wasn't able to dig them out for this review, but I suspect that they would make moves in the otherwise simplistic control scheme easier to distinguish. As it was, I found it very easy to launch powerful multiple hit combos, but more difficult to do simple things like block and defend.
A fighting game demands an option to play against others online, and TvC does oblige, but it is hindered by the limitations of the console itself, which doesn't have good online options built in, thus leaving it to each game to implement its own multiplayer options. Unfortunately, I cannot get connected to the Nintendo Wi-Fi Connection, so I haven't been able to try the online multiplayer yet.
All in all, this is a great fighting game, and I highly recommend it for those who (1) only have a Wii for gaming, (2) are new to fighting games, or (3) who love the Capcom or Tatsunoko characters. This is one of the best fighters out in a while and one that can be enjoyed by a broad range of gamers.