All the words and phrases that are used often... I wouldn't be that good at doing this, but someone who is more able can start. Hell I will start with one of the more used insults.

Fucktard- noun.
1) one who makes some sort of effort to say something witty or intelligent, but comes no where close in doing so, thereby making an ass and moron out of themselves. Example: Zagggon is a fucktard

2) an individual who lacks any sort of intelligence, especially when making a half ass response
Example: Zagggon is a fucktard