Sarcasm

[LFS]

If sarcasm is the lowest form of wit, what is the full list of "wits" or where can it be found?

[sgs]

There is no actual 'list' of wits per se. The phrase means that the use of sarcasm is the least intelligent use of your mental and verbal faculties. Which is, of course, nonsense, as sarcasm in its many forms can be one of the most effective weapons. The only sense in which wits might be a considered a list is in the very archaic use of the 'five wits' to mean the 'five bodily senses' of taste, smell, touch, sight and hearing.

[northernsoul]

you might also want to look up the entry for 'humour' in Fowler's Modern English Usage. He identifies eight types amd describes each according to their purpose and audience. Very useful.