There are plenty of great games for the Wii...You just need some Gamecube controllers. I got 4 3rd party ones for £8 and they work fine. Once you have them, grab Luigi's Mansion, Mario Sunshine, Super Smash Bros Brawl, The Metroid Prime Trilogy (actually the whole lots been ported to the wii, so get that) and Mario Kart: Double Dash.
If your just looking for Wii games get Mario Galaxy (an amazing game) No More Heroes (weird as hell) and Twilight Princess (can't go wrong with Zelda).
Though seriously, the Wii is a dead end console. If you don't want to splash out just get a PS2 for less than £30, you'll have a HUGE catalogue then.