Sometimes I think the best dates are the the ones where little to no money is spent. Russ and I have, on occasion, gotten our girls out of the house for an overnighter just to come home and be with each other.
A walk in the park or to an arboretum is a good idea. My mom said that when she and my dad were broke, they would go to a restaurant, decide on one thing and then split it. Then, they'd take a walk afterwards.
Movies are overrated in my opinion as far as dates go. It's more important to spend time interacting than just sitting together. Bowling is fun and I'm a huge fan of skating.
But as I ma married and am allowed to do other "activities", it's hard for me to be creative.