The whole "gimmick" for the wii is a) interactive (i.e. motion based moves) and b) family/casual style
I have to say that the novelty of the interactive-ness wears off. When I play video games, it's usually when I'm too tired for other things so I am sitting down etc and not really in to the handwaves, etc needed to move in some games.
However, if you know that you can play a video game when you still have energy to swing/move etc then by all means, it can be quite fun (especially as a shared family experience).
Wii sports comes with it, so you'll get some stuff like tennis and bowling along with others (for me, the tennis one is the most enjoyable out of the whole set).
Another game I have been enjoying is Mario Kart Wii. Just simple chaotic racing.
Other stuff I do enjoy on my wii are the Virtule consol games (you can (for a fee) download older nintendo games, like super mario brothers and legend of zelda ...) and since i grew up on those games I really enjoy that (plus they let me just _sit there_ and play rather than motion interactivity).
I did try out some of the party games (like mario party 8) but, really, it was a big pile of mini games as you moved around the board.... it just didn't appeal to me (or my group of friends) at all.
I've heard good things about boomblox for family style fun (think Jenga but unlike that game, you _want_ to get all the blocks to fall when you whack at the tower)
If you're in it for hardcore gaming, you will be dissapointed -- graphics are lacking (esp if you're used to your xbox) and hardcore titles are really sparse. So you have to go in to it specifically for the family style games or else you'll just feel like it was a waste.
I was at one time considering getting the wii fit (it lets you do balance board style games and excersis with the wii) but I know (based on how quickly the novelty of interactive arm motion wore off for me) that the leg motion interactivity would also wear thin eventually too.
Out of everything I have on the wii, when i'm by myself, it's just the old downloaded virtule console games that I play. When I have a friend or two over, we play either wii sports or wii kart.
Unlike other consoles, when finding games, you aren't just considering graphics, game play, sound, etc. but you also have to consider how intuitive the motion control is going to be, or else you'll just be frustrated with the game (for instance, I absolutely love Mteroid 3 prime corruption -- some of the best graphics i've found for the wii and really feels like you're in a movie despite the fact that i normally don't like FPS games; but I just can't seem to do some of the motion controls fast enough meaning I am stuck at a point in the game and can't get past it to the point where i'm frustrated and haven't touched that game since).
Despite everything I said, I do like the console and don't regret purchasing it. But just be aware that it isn't for hardcore gaming, and the novelty of interactive controls may wear thin. But it is great for casual gaming - just stick to titles you know you and your wife would be in to (Wii Sports that comes with the console and Mario Kart Wii are good multiplayer starters)
