As for cheap/free dates:

1. I see someone already mentioned the happy hour idea.
2. An oldie but goodie is to cook for her and rent a movie.
3. Save up Coke Rewards (ask friends and family, too — even check at work in the recycle bin) and get the free movie passes.
4. Entertainment book always has good coupons. (Assuming that you’re comfortable using those on a date.)
5. Check your local papers and try to get passes to movie screenings.
6. Take a hike; bring some nice snacks to have a picnic partway through.
7. If it isn’t too painful for you, do some window shopping. Stroll through funky stores, and see what the other person notices. It can say a lot about one’s personality.
8. Most museums have a free day once a month.
9. Use reward programs to get gift cards for restaurants. This will either let you get free food or will deeply discount the price.
10. Take up mystery shopping (www.volition.com has free resources for this kind of thing) and take her out to meals that way. You have to note a few details, but I’ve done restaurant shops, bar shops and even gaming center/restaurant shops. You have to put up the money up front, but you get reimbursed and even get a few bucks. (Also great are hotel shops! You get a free room, room service and a meal or drinks in the hotel restaurant.)
11. Find some of the more affordable clubs and go out dancing. Don’t have drinks and it can be a pretty frugal night out.

Finally, I think sometimes you just have to weed out those people who have different priorities. I’ve never been one to expect a lot of money be spent on me. If the person you date always wants to do expensive things, or is always frustrated that you mainly stay at home and watch movies, well that’s probably not a good person to date. Of course, it sucks at the time. But even once you get out of debt, that is the kind of person who will tempt you back into your spending ways.