Well, it depends on what was happening.
Something really bad about to happen to me, like a jet about to launch a missile on my position;
"Aw, come on, gimme a break!"
I somehow manage to survive and something worse happens;
"You've gotta be fucking kidding me..."
Someone says something I find very stupid;
"Stop flapping your lips and making sounds come out; none of it is useful for anything except inducing headaches."
Same as above but worse;
I wouldn't say anything; I'd just glare at them, filled with contempt.
Self-explanatory, really;
"Well... we're screwed."
An 'Ask a stupid question, get a stupid answer' scenario.
"No."
"Did you really just ask that?"
"What did I JUST say?"
"42."
"The Game."
"(sarcastically)You are indeed a very intelligent man/woman."
Just off the top of my head.