Please take note of where you're posting a thread before making it. Anything game related, as its board description states, goes on the General Gaming Discussion board.
Anyways, there are a few I'd recommend. Super Paper Mario is a definite rent, if not an out-right purchase. From the Wii games I've played, it's probably one of the most unique and fun on the console to date - especially if you liked the original Paper Mario games. Then there's Elebits, and if you've played the Katamari Damacy games on PS2/PSP and enjoyed 'em you'd probably like it, too. Wario Ware: Smooth Moves can also be a fun game to have around and waste time on.
Really, it all depends on your tastes in games. Sonic and the Secret Rings has a few faults to it, but a lot of people also hail it as one of the best 3D Sonic games yet (I haven't played it myself, tho). Then there's also games like Super Monkey Ball: Banana Blitz, which may not be your first choice but not a bad purchase by any means either.
Still, the best of Wii has yet to come, so keep watching the release lists. There's also the Virtual Console if you feel like diving into some old school games.