the best of the best has already been said, so I'll say some of the rest ;)
Super Paper Mario is a great choice, i honestly don't think that game gets the recognition it deserves. Keeping on the Paper Mario thing, PM64 is on VC if you haven't tried that one.
Boom Blox. Great title, fun and addictive. There is also a sequel for this coming up!
Wario Land: The Shake Dimension is another lovely game worth the cash.
Deadly Creatures is another cool title. Though it may seem dodgy, it actually plays very well, and it great fun.
If you missed out on some Gamecube games then the New Play Control! range is seriously worth the go.
On the Wiiware side of things, i recommend Mega Man 9, World of Goo, Toki Tori, Bomberman Blast and Groovin' Blocks.
There's also a broad library of amazing retro titles up for download on the Shop Channel, you're bound to find something you like.
Honestly, there's a sea of great games beyond Ubisoft's crap. Don't listen to all those people complaining about how the Wii has no games.