Ever think you'd see the words "fast paced" and "elevator sim" in the same sentence? Nor did I. But at the same time, I am not surprised; even elevators deserve a chance to shine! And do they ever in this unique mod.
Elevator: Source's premise centers around being stuck in an elevator with strangers. Random–likely weird–strangers. And this elevator will take you and your new found friends (OR ENEMIES) anywhere. You get in an elevator and stop at crazy, randomly generated floors: from a dude playing a guitar, sitting on a chair, to a prehistoric dinosaur who just wants to disembowel you, you'll see it all. It actually seems very compelling and I can only imagine the types of conversations that it will spark.
Also, you can cough and look at your watch. If you weren't sold on the idea, I bet you are now!
All you need is Garry's Mod and a copy Half Life 2 and you're set!