I also liked the Metroid Prime games.
Star Wars Rogue Squadron II: Rogue Leader is a must. Other interesting games are:
Mario Sunshine - not that great, but surely entraining,
Second Sight - a multi console game and I liked the GC version,
Soul Calibur II - of all the versions I prefer the GC version, Link alone makes it better then the rest.
Resident Evil 4 - truly a brilliant game, not that scary, but u can never relax either, although the PS2 version has some more bonus stuff.