Don't bother with a Wii if you are thinking of getting a 360 or a PS3 (which means you likely fall into the "core gamer" category). I haven't turned mine on in months, and the time before that was months too. There really are not that many good games (I have most of the good ones), and quite frankly, when the gesturing gets old, there's nothing to make up for it, because the majority of the actually good games are just too shallow gameplay wise, character wise, and story wise.

It is family friendly and great when you have friends over, but there really isn't anything good for it.

Twilight Princess, Metroid Prime 3, Zack and Wiki, Mario Galaxy, one version or another of Tiger Woods Golf, Wii Sports, Wii Play, Wario Ware Smooth Moves and Super Smash Brothers Brawl.
For wiiware and classic: Samurai Showdown 1&2, the Final Fantasy sim-city clone, Gunstar Heroes, Puyo Puyo 2, and Zelda: A Link to the Past.

I bought World of Goo through Steam on the PC instead

You are far better off with your DS. It has a much larger library, and a lot of the games have more playability than the games on the Wii.