I hear the GT racing one is terrible. I was expecting a lot from that, but screens dashed my hopes. Example
here
Excitetruck looks a lot of fun, but might be worth hiring first. I saw it at a local games expo before launch here, and it looked very nice. Queues were long though, and I thought I'd rather save the experience for home.
Also, the Dragonball game is high on my lists. Been years since I saw the series, and never played any games before, but this one looks great. Apparently most of the actions are performed through the Wiimote, which is where a lot of skill comes into play, rather than button bashing. It's also available for PS2, but reviews I've read state that the Wii is better for the controls, resulting in different (and better, I hear) gameplay elements it brings to the experience. You can also change voices to the original Japanese cast. This is a huge bonus for me, as I tend to steer clear of all dubs (anime or otherwise)
Warioware will be released in 2 days where I live. I was a little sceptical of the GC version - until I played it. With 2-4 people playing, you'll have a blast. Heaps of fun.
As mentioned above, Zelda is a must own. Looks and sounds fantastic, and brings a lot of new and classic elements to the series. Lots to keep you entertained for quite a while. I've clocked up more than 50 hours, and still have a few collectibles to get.
I hear Nintendo are working on the next Zelda already...
Red Steel was enjoyable for me, but the controls have some serious glitches. These can be fixed through the Wiimote settings (through the home button, turn either rumble or remote vol. off) Overall it was a very enjoyable game for me. Great looking levels and some new and interesting gameplay options.
Steer clear of Farcry for Wii. I loved the xbox version, but this one is quite terrible. Textures are awful, and I think some features were left out. IGN questions if it would run on the N64
If Elebits is out there, that should be worth a look. I believe you can create custom levels and share them online for others to try.
That's about all I can think of for now - there aren't many titles out where I live, so I've only got a few games (except for Sports and Wii Play)