A few times....
Hung myself with a rope in a closet, (suffocating, not a drop), passed out unconscious, felt like my eyes were going to pop out of my skull from the pressure. When I fell over I made a *thump* on the wall, mother came over and found me unconscious, pulled off the rope, and I went to a psychiatric facility the next day.... Sigh, I was fucking 12 back then.
Two years ago (Age 21), had a hard depressive spell, said "fuck it, it ends now", planned to mix a depressant with a depressant. Alcohol and about 60 mg of risperdal. Once you pass out with the alcohol, the risperdal will kick in and your breathing will slow. Well.... drink the alcohol before.. (dur). If I were to do it again, I would down a crapload of downers 20 mins after drinking a lot of scotch. Well, the risperdal caused me to go into tachycardia, basically your heart pumps super hard and misses beats and you get dizzy. Absolutely horrible hour of my life until I passed out.
Oddly enough, about three months after that, I saw The Girl Who Leapt Through Time, and it connected so strongly with me, that I give every single day my best now. I've got incredible drive, have a wicked sick job at a fiber-backbone, a car, and life is great. Now I finally don't want to die =]