Thanks for all the suggestions, but it looks like my concerns have been confirmed. I've gotten Metroid Prime 3: Corruption (which is pretty good), and it may be a while before I pick up anymore games.
The only other games I'm considering are Okami, Super Mario Galaxy, and Tales of Symphonia: Dawn of the New World. I might consider Smash Bros Brawl if I can't find anything better, because Melee was mildly interesting to play through and unlock stuff in.
The main problem with most of the other suggestions is that they're more fun in multiplayer, and I don't really play with friends. New Super Mario Bros. Wii isn't really my cup of tea... I've played it, and it just doesn't really seem like there's much reason to play that instead of one of the many platformers released during the SNES days.
It really does seem like the Wii is geared towards multiplayer games and fun/quirky concepts rather than the kind of games I tend to be interested in playing. Most of the best games are sports, multiplayer, and re-releases of GCN titles with new controls. I hate sports, can't do multiplayer unless I try to use two controllers, and don't see much point in the same games with new controls when I honestly prefer the GCN controller. But I do have to admit... that Crystal Bearers game is starting to grow on me. Mostly because the mini-games and collection/achievements are interesting to unlock. If the aiming controls weren't so jumpy and combat wasn't so hard on my wrist, it could have been an awesome game.
One thing I will never understand, for the life of me, is why people like Guitar Hero. I'd rather just buy a CD or an MP3 and listen to a professional sing.
As for the person who suggested the GCN games... that's nice of you to remind me I can play them on the Wii, but I already have all of the games you suggested, and I know they're pretty good. I had a lot of time to collect GCN games, because just got the HD cables for my GCN and held out until last Christmas to get a Wii. I have to say, part of the reason I held out was because I was hoping that after three years, we'd have a better library of decent games. I got the GCN on release, but at first there weren't many good games. What's sad is that after three years, the Wii only now has as many good games as the GCN did on release. Sigh.
Thanks again for pointing out all the interesting games, though.