I can understand people only voting for recent sitcoms because they haven't seen the others... but Inbetweeners over Gavin & Stacey? Madness, I tell you. Sheer madness.
The only 21st century sitcoms (british) that deserve legendary status are The Office, G&S, Peep Show, Car Share and Extras (excluding ones that ran into the 21st century like Royle Family, Vicar of Dibley, etc)
I'd even vote for 'Rev' over Friday Night Dinner