I'd fish out that last blunt I'd saved for this particular situation give my loaded gun to the guy beside me light up and ask him for 3 requests
1. Let me finish my blunt
2. Make sure I'm dead and coming back before you shoot me
3. Whatever you do DON'T MISS
I would probly go along the lines of puffing away at my cigar while playing with what ever explosive/Incinery device and laugh to a sigh and mutter guess im clocking out early.
I wouldn't talk. I think i'd just shoot myself in the head, while i am human. And if i'd have to talk i'd say something like "I have no regrets" and then shoot myself.
If I did not have a weapon handy I would probably say "Well this certainly sucks.". However if I had my sidearm on me before blowing my brains out I would say "Long live the new flesh.".