Just finished Paper Mario: Sticker Star (which I quite enjoyed, despite its reputation). Not sure what I'm going to play next. My wife and I were going to buy Smash Bros for 3DS on its release date, but we learned I'd have to buy two copies to play each other, which turned us off on that.
Still, I have a backlog here, so maybe Legend of Zelda: Spirit Tracks next.
Edit: I've never dropped a Zelda game so quickly in my life. I like Zelda for the world-exploring, the dungeon-crawling, and the boss-fighting, but after playing it for a half-hour or so I got none of that, just irritating mini-games, a horrible control scheme, way too many cutscenes, and a stealth mission that, after failing it several times because the screen is too zoomed in to actually see where the guards I'm supposed to avoid are, made me shut the game off and stop playing it. Link doesn't even have a sword yet! I have zero urge to go back to it.