1) Jumping from a mere eight stories sounds iffy, like it would depend on how you landed and you'll definitely be trying to survive once you jump so you might not manage to get headfirst.

2) Kneeling in front of a train might work. Terry did it, so I guess this might be an option.

3) Could also work, provided you wear dark clothing and move quickly.

4) Drowning is painful, and if you manage to get the barbell off halfway through, you'll live to regret the whole thing.

5) Bears are scared of you. You'd be more likely to die painfully of exposure maybe after several months, provided you don't find a road out and nobody else finds you

6) Social suicide is not suicide.

7) This... would take a while. As in years of careful planing.

8) Good luck finding a pilot cool with you dying in their plane.

9) You'd probably vomit, then survive with permanent scarring, not recommended without years of training in zen and meditation.

I'm in no position to stop you, just want to save the world some pain and misery. Hope your day gets better :)