Super Mario is really really fun if you at all liked Mario 64.
The virtual console is extremely appealing if you're an old school gamer. Plenty of good games on there. Wiiware is coming out soon and will have a bunch of indie games. Simple and fun usually.
Wii sports and Wii play are fun and Wii Fit is coming out soon. There are a decent amount of good games out now but I think in terms of variety next year the Wii will get a lot of good games.
Still if you're spending that much on a TV I would get a Wii. Its worth the price.