Spend $5 on each other at DI, Savers or other thrift store
This one comes from my favorite sister-in-law, Jenna.
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)
Enjoy the funny looks you will get!
We have yet to document this one. Please let us know if you try it!