Recommend Mario Kart DS, Trauma Center: Under the Knife 2, and Legend of Zelda: Phantom Hourglass. Or, you might want to get some Gameboy Advance games. Metroid Fusion, the Super Mario Advance series, or Pokemon Leaf Green/Fire Red are some of my personal favorites.
I'm surprised no one noticed that this thread is in the wrong forum. Yeah, most definitely should get moved to the Video Games Forum.
Being a Fire Emblem fan and living in Japan, I already have Shadow Dragon for the DS. It's a recreation of the NES game of it, so it might be a little different than the ones you guys are used to. There was no weapon triangle to begin with, so when the DS version came out, it was messed up slightly. How, you ask? That's for you to find out =)