I like one specially, as dead as a dodo, I try to use it as much as I can.

I wouldn't actually call it a favourite because I've never thought about it before. But the first term that came to my mind is "fucko". I like it! There are expressions which mean the same probably in any language but you just can't translate it literally.

For example, when you talk about a process and say, "And Bob's your uncle." At which point the other person will say, "and Fanny's your aunt."

I know af (cool af!) but what does punk mean?

Punk or af