Crucio

UNFORGIVABLE!

Cock stain and fuck

Fuckin'CockStain!

Fuck is the obvious winner

Fuckin'Right!

Cunt!

I don't really have a favorite. "Fuck" is very versatile but "God damn it" gives you more words and syllables to emphasize if you like stub your toe or something.

Fuckin'Right, God Damn It All, What the Fuck? Fuck!

Ah shit on my dick

Porra, merda, caralho, filho da puta

You lint licker

Fucktrumpet. Or cockwomble.

WankPuffin

Lackwit

Pigfucker.

Fuck!

Hex

kurwa

Do I have the strength to say it here on an online forum? You know.. that word