ZACK & WIKI!!!!
Seriously, if Mario Galaxy didn't exist, this would be the best game on Wii. I absolutely love it. It's a sort of puzzle/adventure game hybrid. The puzzles play out similar to old school point and click adventure games (Sam & Max, Monkey Island, etc.) but it's only similar to those games in the puzzles. Basically, you pick an area to go to and it's a self-contained level with all the items and events you need to solve the puzzle and get the treasure chest. It's made by Capcom and I get a real old-school Capcom vibe from it (arcade/NES/SNES era). Characters are a little bit kiddy looking, and very Japanese which I think is turning a lot of people off thinking it's a kid's game. Kid's will just be frustrated by it because of the puzzles. Graphics are actually really good, some of the best on the system.
Others:
Resident Evil 4 Wii Edition: If you haven't played it before, Wii controls make it perfect.
Resident Evil Umbrella Chronicles: I'm renting it now. It's a fun, on-rails light gun/shooter hybrid. It's tough and gets annoying at times but I mostly like it. Might want to rent it first.
Ghost Squad: If you love light-gun games, this is a must buy at $30. Otherwise rent or wait till it's ~$20. It's a port of a Sega arcade light gun game so it's only a half hour long, but there's tons to unlock and online ranking 'n junk. I guess it calibrates with the Wii Zapper really well and feels just like a real light gun. Don't have the Zapper yet so I don't know for sure.
Excite Truck: You can blow through it in a weekend, but it's a helluva lot of fun. Don't pay more than $30 for it.
Rayman Raving Rabbids: Great party game, I liked it a lot better than Wario Ware and Mario Party 8. I guess the sequel just came out, but reviews indicate it's not as good as the first.
Fire Emblem: It's FE, it's good.
Battalion Wars 2 (BWii): It's the Advance Wars RTS spin off game. Never played it, but I've heard it's really good. Also has online co-op.
Medal of Honor Heroes 2: Haven't played this either, but people are going ape-**** over it.
SSX Blur: The controls in this are very odd and it seems to be a love it or hate it kind of game. I liked it quite a bit, but it did grow old fast.
Lego Star Wars Complete Saga: If you haven't played them before, they're a lotta fun. If you've already played them before, there's not really enough new here to make it worthwhile.
Trauma Center 1 & 2: Haven't played them, but hear good things.
Games people seem to like that I didn't:
Sonic & the Secret Rings: Awesome looking and great sense of speed but the controls absolutely ruined it for me.
Cooking Mama: Horrible wii controls. Stick to the DS version.
WarioWare Smooth Moves: Horribly short, so-so minigames.
