Spend $5 on each other at DI, Savers or other thrift store
It can be pretty comical (and impressive) to see what kind of clothes you can get at a thrift store for $5. Pick out outfits for each other (or for yourself) using no more than a pre-set budget ($5 is plenty), then wear the outfits to do one of the other date ideas (bowling, ice skating, etc)