Mostly I don't say "never" but I'm pretty sure about these:

I'll never hunt animals for recreation.
I'll never inflict pain on others for personal enjoyment
I'll never attend a funeral, even of someone I don't know, without crying.
And I'm pretty damn positive I'll never walk on the moon.

Beyond that, who knows?

all the generic stuff doesnt apply to me...i can try anything once
among the stuff i wudnt do:

go near spiders
smoke
attempt cybersex as a guy(its sooo damn boring)
be a jerk for too long
slap someone(ill just punch their lights out)
more stuff i wont post

1) Say never.

Now, onto things that, to my knowledge and judging from my current moral, emotional, and mental standpoint, I strongly doubt I would do:

1) Slap the Queen of England with my penis.
2) Eat fecal matter.
3) Get it on with a dude.
4) Kill an old lady by throwing baby kittens at her.
5) Intentionally pee on myself.
6) Lick any surface of a public transit vehicle.

I can't say right now there's nothing I wouldn't do, ever. You never know what will happen in the future. Or what will make you do certain things in certain situations. I could say I would never kill anyone, but if someone was trying to kill me, I would ram a steak knife in their throat.

I would say I would never have sex with a man, but if someone offered me a million bucks, I'd fuck like an animal.