Even though it's not always the most beginner friendly game, you should seriously consider Monster Hunter 3. It's got online play and dual analogue support, and even if you don't like it you would know to personally avoid the games on Sony platforms.
Also, play the Gamecube games you missed out on through the Wii's full backwards compatibility. You've already decided to get the Wii versions/ports of the 2 Metroid Primes and Zelda TP. Pikmin 2 is also great (get the NPC Wii port with pointer controls), it's predecessor (Pikmin) is also good but not great (but totally worth the £5 one can buy the Wii port for). I'm assuming you've played Resident Evil 4, but the Wii enhanced port is pretty cheap now and is IMO the best version of it. The likes of Paper Mario TTYD, Zelda Wind Waker and Super Mario Sunshine are worth buying for the GC. Keep in mind to play GC games via the Wii, one will require a GC memory card and controller (GC controller is best for SSBBrawl as well, and can be used in games like MKWii).
