Assuming you have friends and family, get TV Party.

Saun White has gotten a lot of good reviews (the Wii version, that is)

Get Shaun White. It got a 78 on metacritic, which is about 15 points higher than the PS3/X360 version. Using the balance board is tons of fun and easy to use (heck even my mom played for a little bit). Doing tricks is another issue. It isn't a control issue, but a keeping your balance issue. I can score high scores, but sometimes it takes multiple runs through the course to not lose my balance half way through.

Also, it is a lot of fun to play multiplayer. Typically the person with the Wii Remote gets a really good score, and the BB player just needs to manage to pull their own weight, but on occasion I managed to outscore my brother while using the BB.

Multiplayer has a Co-Op, Hot seat, and 1 other mode I'm yet to try.

I got Wii Fit + Shaun White + RRR:TV party for christmas and am very happy with all of them. Shaun White controls very good, RRR is some decent multiplayer fun

Wii Music is essential if you have any interest in the drums; the balance board drums mode is incredibly well put together, and by far the best drum simulation on the market.

Contrary to the dumbing-down in Rock Band, which just gives you four colored drums and one pedal to hit DDR style, Wii Music's virtual drumset is exactly like a real one: 2 cymbals, 3 toms, snare, hi-hat opened/closed by your left foot and bass drum controlled with your right foot. On top of that, you can choose from 4 different drumsets, including a jazz set played with brushes. The lessons included walk you through the real basics of drumming, from basic 8-beat patterns to simple variations and fills. You can then, of course, drum over any of the included songs, playing whatever beats and patterns you want, then save a video or start overdubbing all the other instruments.

The sensitivity is such that you can give the drums anything from a light tap or a hard hit, and you can learn to play anything you could play on a real set, but without driving your neighbors crazy or needing to invest in an expensive kit.

If you want to see someone play it well, check this out, or any of this guy's videos (this is not me, I'm not nearly that good yet):

Get Shaun White!, Plus Wii fit is fun with friends try Ski Jumping for example.

RRR TV party is so much fun, assuming you don't play alone.

shaun white is a lot of fun. it really is amazing how much being on the balance board makes you feel like you really are snow boarding so i definitely recommend that one since you have a BB. without the balance board the game is crap.

i haven't played anything else (sans wii fit) that uses the BB but i have a friend that really like RRR.

i like wii fit a lot too but it is what it is...an exercise program. so it's a ton of fun for an exercise program but not really a "game" so to speak.