Dead on with the food idea, VitaminH.
Definately go the sentimental route. What was the first real meal you guys shared?
My last girlfriend (oh, so long ago

) brought me pie for an anniversary. We used to hang out after work (usually late at night) and the first thing I bought her was a slice of pie and a cup of coffee. We went to Shoney's after work with a few folks and eventually it was just us. She didn't have any money on her, so I offered to pick up the check. It was the straw that broke the camel's back, so to speak, and she decided then and there that I was dateable material. A year later, money was tight and I was upset that I didn't have much to spend on her, so, I made her dinner and she brought the pie (from Shoney's even). It was one of the nicest and sweetest things a woman has ever done for me.
/anecdotal threadjack