Nice work Aaron! Welcome to the next gen of extreme dating! gaming! err.
Braid is cool - doesn't seem very girlfriend friendly - more of a guys puzzle game. Let me run off some of my sweet Live Arcade titles you guys might dig.
UNO - everyone loves UNO. It's cheap (400 points or something?) and if you ponied up for the Gold membership, there's always online games over Live - chicks dig it.
Castle Crashers - It's a beat-em-up sorta ala the old arcade TMNT game but with sorta RPG elements and just the greatest hand-drawn art. 4 player same machine or over Live gameplay - it's a fuckin' rad game, no regrets. (I don't know how gf-friendly it is - try the demo, maybe she'll like it.)
Girls apparently love those goddamn horrible Lego games. I hate them very much. Lego Batman just came out, feels like Lego Indianar Wars. HATE! But girls and their sappy boyfriends LOVE!
Ok, I'm totally boring the hell out of myself, so let me rundown really quick what I've played and generally have mass appeal and are awesome games.
TRY THESE DEMOS:
Ticket to Ride
Carcassanne
Catan
Lumines
Puzzle Quest
Pac-Man: Championship Edition
Prolly not so chick friendly (but my personal faves):
N+
Geometry Wars 2
Ok, I'm going to stop. Egads.