I answered play sports, but that's not really relaxing for me, it's what beats the stress for me. I love ice skating, and it feels great when I'm stressed, as soon as I step into the rink, everything else melts away and nothing else exists except for me and the ice. There has actually been times when I would need to take a day off work because it was just too damn stressful, and I would skate for 4-5 hours during the day, and it felt sooo good. Helps me stay centered. I actually chose which school to apply to based on how many rinks there were nearby and how much ice time they had available, and no, I'm not ashamed to admit it.
Although if I wanted to relax, I would probably go for a nice dinner with a couple good friends and laugh about nothing like we do. But that doesn't help me destress, just helps me remember I'm still human.