First off: ItsaMii you cheated by putting "or"...
Now onto mine.
This isn't really my "top 5" it's more like what I'm looking at as quality and fun looking.
de Blob - at first I wasn't excited for this at all. It was originally a game created by students. I thought it was going to turn out to be shovel ware. But now I see there is a lot of deep platforming and exploration. There's a bunch of levels with a many objectives (read: things to do). The game is gorgeous on top of all of that.
Guitar Hero World Tour - Another game I was not looking forward to. But then there was the song creator. If that wasn't enough, then they announce that the circumvented storage problems on Wii by loading directly from the SD card. Nintendo makes things hard, and the big guys have done what they can. Activision fixing storage and EA fixing online service with EA Nation have shown a very nice commitment to the core gamer on Wii.
Little King Story - One of the most powerful parts of the Wii for core gamers is the pointer. I made a thread about it before. Little King Story does so much with such a small range of controls.
SPRay - Vomit power FTW! I like RPGs and Platforming. It's no secret. The idea of combining platforming with creatures who "spray" different materials and fluids so you can climb, slide, break, and more. More? You had me at climb.
Mushroom Men: The Spore Wars - I hate Gamecock. They have been all talk. But suddenly this is starting to shape up real nice.
I would cite regulation, but I know you will simply ignore it.
