Games for a Girlfriend/wife

The Longest Journey. If she doesn't like it just dump her, it's not worth it.

FTL

trine 1+2
rayman：origins
Deponia？（and other point n click games?)
Bejelewed 3
plants vs zombies

any LEGO game

Sims 3, Deponia, Don't Starve, Monkey Island, The Walking Dead...

aaaaand

Skyrim if you don't want any sexy time for a looong looong time ;_; (Even Mass Effect and Dragon Age Origins have the same effect)

Hide and Seek: Cock Edition (best hidden object game out there)

Where's Waldo

Castle Crashers :D , Or Torchlight II ^_^

The cave :)

it depends! is she an imaginary or real?

mine actually plays,

binding of isaac,

dungeons of dredmore,

postal 2,

various adventure games

Walking Dead - the game by telltale

Trine 1 or portal 2 ^^

Plants vs Zombies , Darksiders 2 nice puzzle game , action , adventure ....

Fraerie solitaire

Bejeweled 3 & Civ 4

My wife hates gaming but loves these two games :)

The Binding of Isaac and play Super Meat Boy together :D if not then, Machinarium, Unmechanical, Edna and Harvey: Harvey's new eyes (or anything by Daedalic : Deponia)

I had been trying on and off to get both my sister and my gf (both of them not even "casual" gamers) into gaming at various times and the only thing that didn't make them run away after five minutes was Audiosurf.

Trine 1&2
Portal 1&2

Portal 2

Both Portal games, TRAUMA, Trine. Most Indie Games and most point-and-click games (puzzle agent, monkey island). I'd say that's what any person who aren't used to games should/could start with. Nothing too advanced, yet some magnificent games.

Plain and simple. The one she likes/will like. Don't make artificial divisions.