I have spent my first hours with Nintendo Wii at friend's house. Had a couple of beers and tons of fun with Wii Sports. We just couldn't stop and my right arm hurts if I try to lift it over my head.
So how was it? It's fun. Fun, fun, fun. Because it's simple & dynamic. And because you get really involved after couple games and drinks. Cursing, cheering and screaming is part of it. I liked tennis the best, then bowling and golf. Box is not bad, but I didn't fall for baseball.
You can see from the last picture I played way too much tennis for one night. My armed actually hurt the next day.