my bf got a city pass for Seattle... we could do all sorts of stuff like go to the zoo, aquarium, pacific science center, space needle, etc. For Valentine's Day he made me dinner (chicken alfredo).. and it was soooo good! And he doesn't even know how to cook, but he took the time to make the dish for me so it was even sweeter. I would do something like that.. take her on a picnic.. somewhere romantic, make an album of u guys (take all the pics you have of both of u guys and put it in a nice book- you can get those at the craft store).
But all in all, surprises are the best. You should blindfold her when u pick her up and not tell her what you're doing, no matter what it is, then surprise her when u get to ur destination! Good luck, and let us kno what u ended up doing!