Of things I can control, usually a gaming session calms me (school is my only stress, I don't have much to complain about thankfully), but only certain games. A good session of CK II or some other non-stressful strategy game like Civ5 is best. STALKER or System Shock 2 are not good for relieving stress

Reading is good too though I tend not tp enjoy reading during the term (enough reading as it is).

A good thunderstorm is always best though I can't control those (yet), especially since I have a forest behind my house.

And oddly enough, rather aggressive music, mostly Tool or NIN, relaxes me, possibly from venting some anger through song

I'm very, very bad at being able to relax. I guess the things that I find relaxing are "enthusiastic" music (I tend to prefer late '70s/early '80s pop-punk in that regard) and coffee.

Lots of things, but I'll go with music and playing drums.

Thrash metal, playing the guitar, playing video games, sleeping, watching a movie, reading a book, taking a shower, sauna, chocolate, surfing the web. A whole lot of things.

On the other hand, playing video games, watching movies and surfing the web can have other effects than relaxing, depending what game/movie/part of the infinitely mysterious WWW is.

Morphine