I'll add my two cents about what I
wouldn't get for Wii.
Dragon Ball Z Budokai: Tenkaichi 2
I wouldn't touch this with a ten-foot pole. I absolutely love the game on PS2, but there's no way you would be able to play it well enough on Wii. The novelty factor will wear off very quickly, and once you get the hang of it and you are ready to go up against the more difficult CPU settings, you just won't have the physical speed to keep up on the Wii. Doing a full physical motion with the Wii Remote and Nunchuck compared to simply pressing two buttons simultaneously on the PS2? There's just no comparison when it comes to speed. And any DBZ fan knows that it's all about speed.
If you could play the PS2 version against somebody playing on a Wii, you would win every single time. There is just no way you could keep up with rapid button combinations by waving your hands in loops and other strange shapes. It just wouldn't be fun on Wii, it would be like playing in slow motion. And I guarantee that the CPU's AI hasn't been slowed down for the Wii version to compensate. The AI is sickenly fast and relentless on the highest settings; you'll want all the speed you can get to keep up.
Finally, a great game that really emulates the anime well and keeps the speed of gameplay very high, and then slowing it down with the Wii controls? Sure, if we were all DBZ characters in real life, we could do it...
 But that AI is beyond the physical speed limits of a human being if said human being had to motion all of the moves themselves.
There's also the fact that the music in the North American and European versions are really,
really bad. At least with my PS2, I have the option of playing the Japanese version (which I do). The difference is like night and day.
Red Steel
Ouch. Lousy reviews all over the net because of very lousy controls. Said to be full of glitches too. A friend of mine bought it with his Wii and he was so disappointed that he traded it in for credit two days later. I would certainly recommend renting before buying (although I wouldn't even pay the money to rent it, personally). The videos alone show just how lackluster this title is, and they can't even show you how bad the controls are.
Marvel Ultimate Alliance
Again, a situation where the game would play better on other systems. I love the Wii to death, but there's no way I would want to play a game like X-Men Legends 1 or 2 on it when I could play it with a PS2 controller instead. Besides, it was out for the other systems much earlier. You could have played it on them and been done with it long before the Wii even came out.
Other
I wouldn't recommend a few of the other games (such as WarioWare: Smooth Moves, Wii Play and Elebits) as a second game for North American gamers, because waiting so long for your second game is silly when you have games like Rayman Raving Rabbids and Excite Truck to choose from much earlier.