While it is true that some hardcore gamers may not like Wii as much, that is not the case for my husband. My husband is a gamer, but he loves our Wii. Right now he's mostly playing Guitar Hero, but we have lots of other games that he plays as well.
I am most definitely not a hardcore gamer, but there are some games I enjoy. I loved Super Paper Mario (I love Mario in general, but get lost in the 3d games). I am toying with buying Animal Crossing for myself, too. Wii Sports was fun for a while, but I did eventually tire of it (but, I'm just that type of person).
My favorite thing, really, is to have people over and to watch them play!
Here are some slightly-hopefully-helpful tips on the controls.
You definitely want at least two remotes and two nunchucks. They're used on a variety of games.
If you're going to have lots of people over to play, you might want more, but you can always get them gradually.
If you think anyone is going to want to play classic games (you can download old-school games like Super Mario Bros.), you probably want one of the "classic" controllers.
Wii Fit and some of the newer sports type games use the balance board.
There is a steering wheel for Mario Kart, and while I love to use it, it's not neccessary. I also don't think any of the other attachments that turn the remote into other items are neccessary. For instance there is one that turns the remote into a tennis racket. Might be fun, but you definitely don't need it.
Here is one tip for the Wii. Do *not* buy the "wii" brand SD cards. They're soooooooooo expensive, and you can use a regular SD card just fine.
So, quick summary: The Wii is awesome. Start with the basic remote/nunchuck combo, and you can always buy more later.
(do any of you Wii owners have Animal Crossing? Is it worth it?)