Great advice by all in this thread.
For most people who are depressed to the point where nothing motivates, nothing feels good anymore, I'd highly recommend meds as well. Talk to a physician, or better yet, a psychiatrist. They'll start you off on lower doses and see how you respond and take it from there.
Sometimes, after a few years, the meds will stop working, that's a crucial point. Basically, as a good psychiatrist friend explained to me, anti-depressants will help you keep your "head above water". You still have to do things to better your life, to find creative outlets, to take care of yourself in every way. But anti-deps are a great last resort to help you have the energy and clarity of mind to even begin to improve your life.
Besides meds, some other things mentioned in this thread also help me a great deal:
1: Exercise - any type of exercise that makes you sweat, makes you breathe deeply.
2: Creative expression - whatever suits your fancy will be fine. Could be painting, photography, writing, playing guitar or another musical instrument, singing, creating collages etc. It should be an activity you do *away from the computer* and while using your hands or parts of your body.
3: Education - Like Berbs said, going back to school has done wonders for my emotional state.
4: Humour - watching funny things, hanging out around funny people and taking improv/comedy classes are also good ideas. It's not easy to perform, but even if someone reading this doesn't want to do that, watching comedies on tv or better yet on stage can be helpful. Laughter releases certain hormones in our brains that counteract the deficiencies that accompany depression.
5: Animals - Like Aurora, being around animals is very comforting and relaxing and I'd recommend that too for anyone who is feeling depressed. Animals are very communicative and generous (especially dogs and cats, but also horses, and other animals) and can provide a source of non-verbal comfort, which is often what depressed people need.
6: Clearing/cleaning out closets - I find that this helps me too... about twice a year I go through the closets and clean out everything we haven't used in a few months. It makes room for new things (an exciting thought) and it just feels clearer and more breathable in those rooms.