Silent hill shattered memories by far. Dead Space Extraction was very nice too. And if, like me like this game, the underwater graphics in Endless Ocean Blue World look super.

Monster Hunter Tri > Silent Hill : SM > Resident Evil: Darkside Chronicles > Super Mario Galaxy > Metroid Prime 3: Corruption

Yes, there are others, but I guess those above are the top ones.
And also there are some others coming this year lookin promising: Xenoblade, Mario Galaxy 2, Metroid Other M....
And others that we still have to see some material but will probably be stunning: Zelda Wii, The Last Story, Project Sora, Retro Studios Project.

Star Fox Adventres for GC, although probably nobody wants to remember that game.

The Conduit sucks forever and ever.

As for GameCube and Wii games with better graphics than Resident Evil 4, there are none. Except for Super Mario Galaxy and Legend of Zelda: Twilight Princess.

@J.U.N.O

In my opinion SFA wasn´t that bad and the water effects were breathtaking.

the wii version of RE 4 looks alot better then the other versions ps2/gamecube overall, the skin pignent on leon and the charictors is noticable, the lava and water are vary vibrent in the wii version and look awaful in the other 2 versions........... its a bunch of little things that add up and the wii is much more powerful then the gamecube by more then twice and yeah twice is a big diffrence..............more then that vs ps2

going through my 22wii games vs RE4 and I'd say although madworld has color it has a real high poly count vs RE4 (the shapes are better, battalion wars 2 is WAY more vibrant with alot more shine (better looking overall) the conduit isn't on the same level as a video game but it has more color but the art work isn't as good (to many boxes clone enemies, and more of the same) and really thats all out off my games............ actually you got a good point...........

Red Steel 2
Monster Hunter 3

Zelda Wii will destroy RE4.

I ment no color

I know Baten Kaitos Origins used pre-rendered backdrops in the overworld and towns, but that was a damn sexy looking NGC game.