Easy this one. The Simpsons, no argument. 20 years of consistent funniness!! Only Fawlty Towers comes close. Too short a series though. The Office deserves a mention and Cheers at its peak was great. Fools and Horses!! Pheonix Nights!!, sorry I missed the boat on those 2.
blackadder goes forth. fantastic! forgot that one. the last episode was pure genius. when they go over the top, wow, thats great comedy when you can laugh and cry at the same time!!
Brass, The New Statesman (early series),Not the Nine o,clock News, Santa Barbara ( for all the wrong reasons), Nighty Night, Marion and Geoff, Ab Fab & 'The Nativity' Vicar of Dibley.