We’ve bought the following (in addition to Sports, which is a great go-to for parties):
Warioware - Burned through it pretty quickly to unlock all the games and the multiplayer mode… then really haven’t played it since. Once you’ve seen the jokes (and it did have me laughing) once, there’s really not much substance to it.
Rampage - Tacked on motion controls are really weak, but it is quite satisfying when you want to just destroy shit without concern for the game’s quality.
Super Paper Mario - I haven’t really sunk much time into it, but El Perro Fumando is a battle or two away from beating it, and has really enjoyed doing so. What I’ve played has been quite fun.
Madden 07 - I like most of the Wii-centric additions, but it’s not remarkably different than other consoles. Some gameplay is easier on a standard controller.
Sonic and the Secret Rings - Another one I haven’t had much time to sit down and play. What I have played has been pretty fun, but Fumando got tired of it quickly, and a friend of hers who bought it gave up pretty quickly, finding it more work than fun.
Mario Party 8 - From what I understand, it’s not really any improvement over the last two or three iterations of the series, but many of the minigames stand up to repeated play, the board game gimmick tying everything together is compelling (and the five different boards that are used offer a strong sense of variety). It’s been panned for being more of the same, but we’ve been playing (usually together) at least one game a day for the past two weeks. Here’s my sunken thread for the game, which has a lot of impressions as I was first playing through it, unlocking games and getting used to the various boards. I’m still playing it and enjoying it about daily.
For really solid fun games, especially if you’re bringing friends into it, I say Mario Party is where it’s at. Super Paper Mario is a very strong platformer. I’ve been curious about Zelda since release, but haven’t had the time to sit down and play a game for thirty hours, so I haven’t bought it. I’ll wait until Wii builds up enough of a library to start releasing whatever the name will be for their Greatest/Platinum/Whatever Hits, and get it cheaper, so even if I don’t have all the time in the world to play, I won’t care so much.
gazpacho, I got mine at a Best Buy “Members” event, where they held stock of about a dozen systems away from regular public sale. I had a hunch they’d be there, and was right. Also, it seems that Circuit Citys (Cities?) and Targets in the area still do Sunday morning lines/vouchers. Circuit City even advertises such every few weeks in their circular.