The hit show featuring the rogue-trading capers of Del Boy, Rodney and Uncle Albert as Trotter’s Independent Traders ran from 1981 to 2003.
It beat the John Cleese classic Fawlty Towers into second place with Blackadder taking third.
Dad’s Army, the 70s favourite featuring Captain Mainwaring’s ragtag group of WW2 Home Guard volunteers, finished fourth.
Father Ted, along with his fellow hapless priests Dougal and Jack - and the embittered Mrs Doyle completed the top five, in the poll of 2,000 adults by Samsung for World Television Day.
The Inbetweeners’ awkward adventures in their pursuit of sex, drugs and rock ‘n’ roll beat Ronnie Barker’s short-lived 70s prison classic Porridge into sixth.
And Gavin and Stacey, which was created by James Corden and Ruth Jones, came eighth.
Mrs Brown’s Boys, featuring Ireland’s favourite interfering ‘Mammy’ Agnes Brown, and 90s favourite The Vicar of Dibley - featuring Dawn French’s classic Liam Gallagher-loving Geraldine Granger completed the top ten.
Other sitcoms to feature in the top 20 include Craig Charles’ recently-revived cult space spoof Red Dwarf and Joanna Lumley and Jennifer Saunders’ Absolutely Fabulous.
The Office also made the list - as did David Mitchell and Robert Webb’s similarly cringe-worthy Peep Show.
Samsung spokesman Steve Mitchell said: “World Television Day is a great time to look back on some of the great shows we have watched in 2017 but also reflect on some of our favourite series of all time.
“It’s great to see old classics, such as Only Fools & Horses, still entertaining the nation years after they were made.
“Viewing habits are of key importance to us at Samsung, as the No.1 brand in the UK we continue to match our technology to meet the needs of television viewers.
“In 2017 Samsung have the most popular Smart TVs with the largest user base which is down to giving the viewer seamless access to whatever content they want, when they want it.
“So perhaps it is no surprise we are taking advantage of this to re-watch and re-live some of these all-time great shows”.
Brits’ Top 20 Sitcoms
1. Only Fools and Horses
2. Fawlty Towers
4. Dad’s Army
5. Father Ted
6. The Inbetweeners
8. Gavin and Stacey
9. Mrs Brown’s Boys
10. Vicar of Dibley
11. Red Dwarf
12. The Royle Family
13. One Foot in the Grave
14. Absolutely Fabulous
15. The Office
16. The Young Ones
17. Steptoe and Son
18. Peep Show
20. Yes Minister