I believe this may have been posted already, but I’m writing this at a desperate attempt to cure my boredom. Anyway, post your funniest addons you have ever seen on garrysmod.org, or the funniest things you or some other guy have built.
One of my friends made a sex simulator using E2, it’s a bed, with Alyx on all fours. If you press E, your character climbs in an invisible pod under Alyx, and sound clips begin playing. At first you hear “Come on, Gordon!” and Alyx makes sexual moaning noises. After about 20 seconds, you get ejected from the pod and Alyx says “You better reload”. It was the funniest and most clever thing I have seen someone ever make on GMod.