There's isn't another show as VULGAR !
When you really analyze some of the lines and conversations on the inbetweeners (my fav show ever), there really isn't anything which can compare.
All of the other shows which people name as being similar aren't as vulgar as the inbetweeners. The lines are delivered so beautifally in this show that you don't realise how vulgar and inappropriate they really are.
There are jokes about rape, *beep* underage girls, masterbating with your friend's mother's knickers, gang bangs etc etc
Brilliant stuff :)