I just bought a DS Lite for my girlfriend, for her birthday. I got her Nintendogs and Mario Kart first up. I really wanted to get her a whole heap of games, but they get a bit expensive when you add them up.
I envy your girlfriend My boyfriend gave me a DS Lite display box from work ... gee thanks.
And TC is IMO abit naff after a while. Go get Phoenix Wright Ace Attonery!