Number Ten: Getting into a car with a soppy-drunk driver.
Drunk drivers rarely (sadly) die. They're usually too relaxed. The same can be said for their passengers, but only because the passengers are injured in ways too interesting for the surgeons to let go.
Number Nine: Tylenol overdose.
Number Eight: Picking a fight with that aggressive guy at the bar.
Closed-head injuries are never fun. Closed-head injuries sustained because somebody whanged you head-first into the bar multiple times are even less fun.
Number Seven: Car surfing.
Number Six: Setting yourself on fire. More than once.
Look: You wanna die? Ask me. I can give you plenty of great, fool-proof tips. You wanna torture your loved ones? There are better ways of doing that than dousing yourself in some inflammable liquid and lighting a match. The general rule of killing yourself is as follows: If you can do it more than once, you're not doing it right.
Number Five: Falling (or diving) off a high place (or into shallow water) head-first.
At best, you'll end up a paraplegic with a lot of hardware in your spine. The paraplegic part is totally manageable; the hardware part less so, as that stuff eventually ends up working its way out of your spine and through your skin. Plus, given the time you'll spend in the hospital, you'll end up with lots of fun drug-resistant infections and cool bruises and scars. And then there's the whole "not walk again" or "not walk, *plus* not use your hands again" thing, which really kind of sucks.
Number Four: Popping wheelies on a busy highway on a rice-rocket when you're an inexperienced rider.
Number Three: Cocaine or heroin or whatever underdose.
If you're really serious, try something there's no cure for, like polonium or arsenic. Wanna end up in diapers with the mentation of a toddler and a fondness for cuss words? Heroin/coke/whatever is the way to go. If you want to really punish the people who love you, go 'head and have another line/syringeful/whatever.
Number Two: Have a poor understanding of trajectories and ballistics.
And the number one incredibly stupid way to fail utterly to kill yourself?
Stick your head in a combine.