DH and I do the box sets and it's fab - doesn't usually require the attention span of a film (although the Wire does!) and can just do a single episode or have a marathon session if you're in the mood. We loved Six Feet Under, and also enjoy Desperate Housewives, Nip Tuck, Mad Men, 24, Prison Break.
Fantasy life planning can be fun - part of DH would love to pack it all in, move to rural Spain and run a small hotel where he'd cook lovely evening meals and run photography courses. We often talk through what it would be like, what we would do, things we'd try, where it would be etc. All just for fun, but it gets you out of day to day life, and scheming together brings you closer together. Plus one day, if we talk enough, we may convince ourselves to do it!
Cooking together is more relaxing than if one does it - share the chopping, preparation, both do the tasting, hang out in kitchen with a glass of wine while doing it. Somebody talked about doing jigsaws and how you end up talking about other stuff - we find the same happens when cooking together.
We also often look through photos of holidays from before DS - remind ourselves how unknackered beautiful we once were and how much fun we can have as a couple.
Another silly but fun game - we put the iPod on shuffle then have to guess the song and band from the intro! Gets competitive if you keep track of who gets them first