I want to help keep my teenage nephew and niece from being bored on Christmas afternoon when I get them (probably at gunpoint) to have some social time with the rest of the family. Do you have recs for humorous games suitable for teens on up?
Without knowing the details of the players and their tastes, my go-to recommendation is Apples to Apples.
That’s what I was going to recommend, too.
Back when I was a teen we loved Balderdash
Hell, I played it both with my nerd friends and my football team friends. Both loved it. Bullshitting a definition is fun, and often hilarious.
Aye, Nuke War and Illuminati. Both are great fun, and funny. Each only takes maybe 15 minutes to learn how to play, tops.
Another vote for Apples to Apples.
I also might recommend Kill Doctor Lucky, if your family’s sense of humor has a bit of a morbid streak. It’s a reverse version of Clue – all of the players are racing around a mansion, trying to get Doctor Lucky alone so they can off him.
Yes, nothing says “season of peace and goodwill” like reducing the world to a virus-ridden radioactive cinder. “You just looked at me funny - here comes my 200 megaton planet-killer.” 
Our idea of a good game was one where everyone was reduced to the level of population such that the first act of final retaliation triggered a chain that ended with everyone dead, although actually blowing up the world itself was always a bonus.
Illuminati: a minute to learn, a lifetime to finish a &*%! game.
Gloom is a cool card game. The art is heavily, uh, “inspired” by Edward Gorey. Each player takes control of a family. The idea is to make your family a miserable as possible, and then kill them, while doing your best to make your opponent’s families’ lives a little brighter. The winner is the person who’s family accumulates the most misery before finally kicking it. What really makes the game is requiring everyone to narrate exactly what happens whenever you play a card, building on what’s previously been done to the poor bastards.
I’ll give an anti-recommendation to the Munchkin games. They need more than two players to work, and even then, they don’t really work: the game mainly comes down to which Level 9 player’s turn is next once everyone else runs out of ammo to screw them over.
How about a nice game of chess instead?
Back on topic, I’ll nominate Uno–simple to learn, simple to play, and doesn’t take forever.
The idea behind Gloom is ok, but I don’t think that it works as a game. It’s just not really good enough. For card games I’d much rather recommend Bang!, Family Business, Guillotine, or Citadels. Illuminati was recommended above - it’s a bit more difficult and might be a bit too esoteric for a couple of teenagers. Hacker explores the same game mechanics but is a bit easier, IIRC.
For a fun board game you could do worse than the fun little co-op game Red November.
I have tried to recommend relatively cheap, easy-to-learn, quick games here. Have fun!
Hmm. Something weird happened with my quote from Miller. I’ll try again:
The idea behind Gloom is ok, but I don’t think that it works as a game. It’s just not really good enough. For card games I’d much rather recommend Bang!, Family Business, Guillotine, or Citadels. Illuminati was recommended above - it’s a bit more difficult and might be a bit too esoteric for a couple of teenagers. Hacker explores the same game mechanics but is a bit easier, IIRC.
For a fun board game you could do worse than the fun little co-op game Red November.
I have tried to recommend relatively cheap, easy-to-learn, quick games here. Have fun!
Kill Doctor Lucky is great. It was originally created by Cheapass Games, which have a number of great games the OP might like.
And I see on the Cheapass website that Kill Doctor Lucky is available as a free .pdf download! Nice!
ImaginIff is more fun with more players. Basically, the game goes something like this: player A spins the spinner, which points to the name of Player B. Player A then draws a card, which has a question, and reads it aloud to everyone. The questions are something like, “Imagine if Player B were a crime, what crime would he be?” with a list of possible answers, like “joyriding” or “indecent exposure”. Each player has some cards marked A through F, and they pick the card for the answer they like best. Players show their cards at the same time, and those who got the most popular answer get to move forward on the board. The questions are very light-hearted and silly, so no one gets mad, and it’s more of a “learning what people think” game than anything super-competitive.
Agreed – they’ve done a bunch of fun games. Though, my all-time favorite Cheapass Game, “Before I Kill You, Mr. Bond”, was discontinued due to certain copyright issues. 
The two that leaped to mind for me are Zombies! and any of the versions of Fluxx. Both are easily learned, fun, and can be played by anywhere from 2-6 players (although I’d say 4 or 5 is ideal in both cases.
Zombies! is always very popular at games night among our friends, since it’s quick to figure out and who doesn’t like killing zombies? Essentially, you go around the ever-evolving game board, killing zombies, collecting treasure, and trying to screw over everyone else. Good times.
The basic rules of Fluxx are 1 - Draw a card and 2 - Play a card. There is no way to win the game until someone plays a card with the terms for winning. Other new rules can be added by playing other cards, pretty much endlessly. The Monty Python version, which we have, is most effectively played when everyone has a passing knowledge of Python references, but can be handled with fun for all even without.
It got reprinted as James Ernest’s Totally Renamed Spy Game, and I believe it’s still in print under that name.