If you don't already own or haven't played Tomb Raider: Anniversary on PS2 / Xbox 360, pick it up on Wii. The pointer controls improve the shooting a lot, and its a very good game anyway on whatever system you choose. It might help you get interested for the new game thats coming!
Resident Evil 4: Wii Edition is awesome as well, where ports are concerned.
Metroid Prime 3 is probably the best game on the console after Mario Galaxy.
Aside from Medal of Honor, other good online games are Mario Strikers: Charged and Mario Kart. Especially Mario Kart.
See if you can get together 500 points or have someone gift you the Opera Internet Channel. Download a bunch of VC games, have a look at some of the better WiiWare stuff thats out.
Once you do get the Twilight Hack, the first thing you should get is the Homebrew Channel from hackmii.com ... if you like the old LucasArts point and click adventures, grab ScummVM for Wii as well. You can compress talky versions of those games down to 80mb. You'll also be able to launch emulators and stuff with that channel. DON'T upgrade your Wii firmware if you want to do this.