Sorry about the two-day delay. This week we'll present some high-class insults with which to baffle your foes.

troglodyte – 1. a cave-dweller
2. one who is reclusive, reactionary, out of date, or brutish
[from the Greek name of an Ethiopian people, influenced by trogle ‘hole’]

… there were several cars behind him, including one of those pickups that sit about six feet off the ground and are invariably driven by some tailgating troglodyte …
– T.C. Boyle, The Tortilla Curtain

excerebrose – brainless; having no brain

… hackers penetrated a database …, gaining access to the personal files of as many as 32,000 people. … In a contrite but somewhat excerebrose statement, Sanford stated that: "We sincerely regret the circumstances that were recently announced."
– Chris Noon, Lexis Nexis Exec Admits Hackers Took Control Of Database, Forbes, 03.10.05

Two rather archaic words:

recreant – 1. abjectly cowardly 2. disloyal (noun: a recreant person)
poltroon – an utter coward
[Italian, perhaps from poltro ‘lazy’]

'Come hither!' he cried to his servants. 'Come, if you are not all recreant!'
– J.R.R. Tolkien, The Lord of the Rings

I also remember a short storry … about the recreant son of an old family who recovered his courage and vindicated his tarnished honor …
– Thomas Wolfe, You Can't Go Home Again

Go back to your seat, you omadhaun, you poltroon, you thing from the far dark corner of a bog.
– Frank McCourt, Angela's Ashes: A Memoir

Bonus word:
omadhaun – a fool, an idiot, a mentally backward person [Irish]

subdolous - sly; crafty; cunning

Today's quote is enjoyable, but query whether it uses the word correctly.

At his press conference recently the President referred to columnists as "unnecessary excrescence." Mr. Roosevelt was just being subdolous.
– San Mateo, California Times, Jan. 6, 1945

He was being sly, cunning, crafty, and ... artful. Well, whether or not he was artful is a matter of opinion. No? subdolous.

He probably wanted to get the hacks running for their dictionaries to look up "excrescence".

I think my vote still goes to troglodyte as the best word of this kind. It feels so good rolling around in my mouth when I'm feeling uppity.

benighted – ignorant or unenlightened

… a novel constitutional doctrine known as the "right to marital privacy." … "Privacy" functioned as a euphemism for immunity from those public-morals laws deemed by the justices to reflect benighted moral views.
– Robert P. George and David L. Tubbs, National Review, July 18, 2005

There was a young man so benighted,
He didn't know when he was slighted.
He went to a party
And ate just as hearty
As if he'd been really invited.

And here's a rare insult which feels wonderful in the mouth.
slubberdegullion – a slobbering or dirty fellow; a worthless sloven