Fire Emblem: Path of Radiance -- absolute must-buy if you like SRPGs. While I still generally prefer Tactics Ogre SNES/PS uber alles, Dragona is really winning me over to the FE camp.
Batallion Wars -- total crap. Terrible controls/camera, dated mission design, and a generally ugly aesthetic.
Killer 7 -- much as I'd love to dismiss this game, it DOES have a weird sort of pretentious charm. The gameplay is rock bottom, but like one of my favorite non-games, Silent Hill 2, the off-kilter priorities of the game's director make it an amusing playthrough. Just don't expect ANYTHING resembling quality mechanics.
Tales of Symphonia -- crap. The fighting engine is actually quite good, but to experience it, you have to slog through the most cliched characters ever committed to an RPG plot. And speaking of plot, it's pure anime sewage: magical submissive angel girl saves the tree of mana type sewage. Pass.
Donkey Kong: Jungle Beat -- crap. If you MUST have a platformer, buy a GBA Player and Yoshi's Island. This is throwaway platforming fluff of the Yoshi's Story variety given any sort of note solely because of the gimmicky bongo controls. Four hours later, you'll realize you utterly wasted your time.
Prince of Persia 1 or 2 -- get 1, skip 2. 1 is 3D platforming genius. 2 coulda been genius, but they spent so much time designing chainmail bikinis and licensing Godsmack that the few moments of brilliance are separated by swathes of utter mediocrity accompanied by the worst soundtrack of all time. Get the PC or Xbox version of 2 if you must; the GC version has some of the worst 16-bit color artifacts I've ever seen.
Geist -- crap. Second-rate FPS design wed to a possession gimmick that results in second-rate adventure game design. The end result is a third-rate game that does nothing truly right.
Pikmin 2 -- good game. Get it. It gets a bit tedious towards the end, but the Pikmin really ARE fucking cute, and the controls should be considered for other RTS variants in the future. Fun and deep.
Paper Mario RPG 2 -- also great. Like Pikmin 2, it's not without its problems -- the backtracking is wearisome and frequent -- but the kickass battle system and funny, self-deprecating dialogue get me every time. Good, good stuff.