Dancin' in the Ruins

"Go and get your riot gear,
swing your girlie all around.
We'll be dancing on the cinders

as the town is burning down."

—Five Iron Frenzy, "Get Your Riot Gear"

It's not hard to spot this guy (or gal) in an After the End setting: he's the one dancing merrily on the grave of civilization. What his particular beef was with society may vary, but in all cases he's overjoyed to have seen it bite the dust. He's not typically the one responsible for the big boom, though he might shake the hand of whoever is given the opportunity. Could possibly be considered a slightly less insane version of Put Them All Out of My Misery.

Compare Crazy Survivalist, Loners Are Freaks, and Put Them All Out of My Misery. Might become the Token Evil Teammate or The Sour Supporter if he decides he has reason to join up with a group of other survivors (highly doubtful though).

See also While Rome Burns, where the survivor may not be enjoying the carnage, but they certainly don't seem to mind it much.

Examples of Dancin' in the Ruins include:

Literature

Harold Lauder in Stephen King's The Stand. At least he was in the beginning of the book...
The protagonist of H. G. Wells' War of the Worlds did this after he discovered the dead Martians.
Not quite but in The Dresden Files, Changes, Harry says that that if he has to burn the world to save his daughter, he and the kid will roast marshmallows.

Live Action TV

Henry Bemis (Burgess Meredith) in The Twilight Zone episode 'Time Enough At Last'. But then...

Music Videos

Everyone who hears the LMFAO song "Party Rock Anthem" (unwillingly) dances with apocalyptic abandon.

Tabletop RPG

The Doomguard faction in the Dungeons&Dragons setting Planescape has this as their ideal. The end of everything can not be prevented, and is therefore desirable. Some members might regret the suffering of the people that have died, but everything that is completely destroyed really makes their day.

Video Games

In Left 4 Dead and the sequel, we get Francis, who views the zombie apocalypse as "one big barfight" and holds open disdain for everything except vests, and Ellis, who is clearly having a very good time stealing stock cars, running around on roller coasters, and setting off the Midnight Riders pyrotechnics.

Web Comics

This guy from a Medium Large strip.

Western Animation

Homer Simpson during a Treehouse of Horror episode when he happened to be in a bomb shelter when the rest of the world was destroyed by nuclear bombs. One of the first things he did was go to the church, where he danced in his underwear.