I have so far found and finished The inbetweeners, Mrs Browns Boys, and The IT Crowd, and they are some of the greatest funniest British TV shows so far. What other shows would you recommend?

Mrs Brown ? Can't get better British than that.Have you tried German TV?

Only Fools and Horses
Porridge
Blackadder
Dad's Army
Fawlty Towers
Father Ted
The Office
Extras
Open All Hours
Yes Minister/Yes Prime Minister
The Vicar of Dibley
One Foot In The Grave
Rising Damp
Reggie Perrin
Some Mothers Do Ave Em
One Foot In The Grave

British sitcoms that everyone should give a go at least once

This is bit like saying I really like the Sex Pistols, The Damned and The Clash, can you recommend any other British bands? Comedy is a bit like music, it's entirely up to the individual, only seen one episode of the Inbetweeners and Mrs Browns Boys, neither of which I found in the slightest bit funny, but that's taste. Depends on what you like, I'd agree with all the ones from Wheel bar Vicar of Dibley but would add Man About The House, George and Mildred, Citizen Smith and Bless This House. Most modern comedy is attocious except League of Gentleman and Mighty Boosh, you may notice same actors in MB as in the IT Crowd so I'd give that a go, LoG is very dark and surreal and almost Lovecraftian mix of comedy and horror... ARE YOU LOCAL???

I hate people who quote done-to-death comedy lines, but that's only me. I mean, that's me, that is.