If you and your partner particularly like a certain attraction, it may make sense to see if they offer a yearly pass. Yearly passes will allow you to go as many times during the year as you want for one set price. The yearly price will usually pay for iteself after only a few visits.
This will give you an inexpensive date whenever you want throughout the year. You can go as often as you like at no extra cost. most places that offer yearly passes have special events over the year which help to keep things from getting boring.
Those that are younger (and the older folks who like roller coasters) may do well to invest in one of the yearly theme park passes which are becoming more common. For what would be less than paying to enter the amusement park 2 times, you can gain admission as many times as you want during the season.
Similar yearly passes also exist to a wide variety of other attractions. These include such attractions as zoos, museums and parks. By finding an activity that the two of you enjoy, you can save by visiting the place time and again during the year.