i have a 360 and a wii, good balance in my opinion, both are very fun game systems but they are completely different. i'm waiting until a few more games come out for the ps3, it's by far the superior graphics machine, but it's relatively new so i'm giving game producers some time to work with it.
as far as fun games for the wii:
if you like wii sports i'd recommend wii play, it is basically an extension of wii sports and is still pretty fun
wario ware is hilarious, totally random and works well with the wii controls
zelda is sick, if you've played a zelda game you should know what to expect, but its fun with the nunchuck and wiimote
need for speed carbon also kicks ass, being able to tilt the remote to steer > joystick, i'll take better controls over better graphics
resident evil 4 is epic. you can get if for cheap, like 20 bucks or something cause it's actually a game cube game, but its easily one of the best resident evils.
now games to look forward to
i can't wait for super smash bros. one of the main reasons i bought the console.
super mario galaxy is going to rock
mario kart is going to come with a steering wheel attachment. and come on, it's mario kart! who doesn't like playing that game
link's crossbow training is going to come with the zapper, a gun attachment for the controller. should be interesting
resident evil umbrella chronicles is going to be an on rails shooter, designed to work with the zapper. arcade style shooter anyone? i'm stoked.
enjoy your wii dude, and don't forget its backwards compatible, so if you get bored with wii games, you can pick up a gamecube controller and games for cheap. and of course theres the virtual console. it's great because those were all the games i used to play as a kid, and they're still fun!
