World Ends With You has been mentioned twice in this topic? It should get mentioned at least two times per fucking POST it's so damn good. Great Amazing Godly story, the characters were great, food system was cool, clothing system was perfect, and the battle system was nearly (the nearly is just a formality, it's 100% perfect :P) perfect. You basically control every aspect of the difficulty, too. And the inverse level-drop rate relationship was beautiful too. THE definitive DS JRPG out there, and I shed a man tear when there wasn't a sequel announcement at E3. Go buy it. And love it. You're welcome.
Pokemon Emerald. Yeah, I know it's not a Gen II game. Sue me. Gen 3 was the best, and Emerald fixed the somewhat shallow R+S. The story was pretty good albeit predictable from R+S, the Pokemon were great (fuck yeah Swampert), the difficulty was a bit too easy, but just right to a new player. You can always Nuzlocke it if it's too easy. But Lolcat, that doesn't mean it's 10/10, it just means it's good! Well, guess what's at the end of the game. The Battle Frontier. Remember the Crystal and RS Battle Towers? Emerald Battle Frontier was the best addition to a Pokemon game ever. Good for many hundreds of hours of entertainment.
Super Mario Galaxy(1) was a great platformer. The music was amazing, the whole "planet-hopping" deal was great, the graphics (for the Wii) were great, and there were even little pinches of story in there. The Comet Observatory hub was awesome, though not up to Isle Delfino standards -_-// Great game, probably 10/10.
Honorable mentions: DKC2, Super Mario Sunshine, Twilight Princess (fuck you Ocarina TP kicked your ass to the curb), E.T. the video game, M&Ms Kart Racing, Pokemon Battle Revolution, Sonic and the Black Knight oh wait...