I don't know if you plan on picking up the Wii-U early or want to wait for games. For me - I played on a Wii of a friend. This friend was moving to another city late last year - and I decided to wait for the Wii-U. But the Rainfall-RPGs were hitting, and while I expected the Wii-U in Spring, I had to learn that it will come only late in the year. So I changed my plan and were buying the Wii now. That also means, I will get the Wii-U later, probably after a year or so if many of the games I'm interested in are out. I don't know how long you will wait for the Wii-U, on that depends if you should take the Wii for now.
Games: The two Pikmin-remakes for the Wii are good. Take from rainfall Pandora's Tower. I didn't palyed Xenoblade yet (later), but Pandora's Tower > The Last Story. If you have enough money buy both. Take Wii Sport Resort and Super Smash Brtothers (much fun with firends).
For the genres you named: Maybe Fire Emblem: Radiant Dawn, Epic Mickey, Monster Hunter Tri. I'm not too much into platformers, but I always hear Mario Galaxy and Rayman Origins are good. Okami is probably better on PS2, but in that question the opinions differ. But buy the game, for whatever platform.
EDIT: Reading again about the cheap part - you will probably not buy the Wii-U on start and take a Wii now. Also you may wait on the Rainfall-games, they are expensive. All the other stuff is older.