Well, I know you like SRPGs, so I recommend you get Fire Emblem for Gamecube and/or Wii. An absolutely outstanding pair of SRPGs. The two games are directly linked, so you should play the Gamecube one first if you're interested.
In the action/adventure category, I'd recommend that you get the Metroid Prime Trilogy which is coming out in August, I believe. It's a spectacular value. Also try Okami and Resident Evil 4.
Looking at your profile, I see you have Professor Layton. If you're a fan of puzzle solving, I would recommend Zack & Wiki, along with about a million great puzzle games on WiiWare. And if you enjoyed Street Fighter 4, you might want to try a Nintendo-style fighter in Super Smash Bros Brawl, or pick up Tatsunoko vs. Capcom which should be out in the next six months or so.
Personally, I don't think any Wii collection is complete without Mario Kart, but of course some people won't agree.
"The worst part about these reviews is they are [subjective]--and their scores often depend on how drunk you got the media at a Street Fighter event." — Mona Hamilton, Capcom Senior VP of Marketing
*Image indefinitely borrowed from BrainBoxLtd without his consent.
