Klonoa - A remake of the 1997 PS1 game. One of the best platformers ever, without a doubt. In my book, it's second only to Yoshi's Island.
A Boy and His Blob - An adorable adventure game with fantastic 2D art.
Silent Hill: Shattered Memories - Basically what Silent Hill always should have been.
Sin & Punishment 2 - One of the best action games ever made. Really challenging, really fast-paced, and absurdly satisfying.
Tenchu 4 - It's a return to form for the series. Still old-school as all get-out (in case that sorta thing bothers you), but it's a true stealth game.
Punch Out - Seems like nobody really played the game, but... it's Punch Out. And it's phenomenal. It's a bullshit-free game from Nintendo!
No More Heroes 2 - Not a whole lot of people played the sequel, but I felt like it was better than the original in just about every way. Plus, the 8-bit mini games are rad.
There's a lot more, but those are the first bunch of games that came to mind. The Wii is a much better system than people realize.