If it's less than 2 days:
Relax (watch tv)
Take a drive
Play X-box
Spend time with people who's names I've forgotten cause I havn't seen them in so long.....(my signifcant other somehow falls into this category)
More than 5 days:
LEAVE THE COUNTRY!!!
Seriously, every single time I've gotten more than 5 days off (happens about 1.5 times a year), I go to Vancouver. There's something about that city that I absolutely love. Plus having friends to get debaucherous with also helps. No talking about the "biz", or recording, it's all "hey man, wanna beer?" "or "dude, let's go play some street hockey!!" I don't think I'll ever grow out of wanting to hear that last phrase.