There are a few things to do in Grapevine. I lived downtown and worked at Willhoites for a while.
Take a stroll through downtown.. a lot of shops to check out. Willhoites is a good place to get a beer.
Hit Bone Daddy's for some good BBQ. Scenery is top notch too
Best BBQ beans and cold ass 32oz beers!
The Gaylord Hotel is a lot of fun to walk through.
I would stay far away from Dallas.
If you play golf I would suggest a day at Cowboys.