Sea Battle Challenge
Due to a seriously good suggestion in the forums it's time for people to get ship-building.
Create a sea battle using GMod and go to the challenges section and post it.
Try to put some effort in as the challenge is a two week long one to allow people to build something impressive.
The Idiots Of Garry
This has been out for a while, but here's a sketch show based on/in GMod.
For more details the thread can be found here.