Hosted by Ulrika Jonsson and John Fashanu whose catchphrase was ‘Awooga!’ – from 1992 until 2000.
It returned to screens this year with Bradley Walsh and his son Barney.
Second was Countdown, then The Chase, Deal or No Deal, and Pointless.
Next came Who Wants to Be a Millionaire?, Catchphrase, Tipping Point, Mastermind and University Challenge.
Just outside the top ten were Bullseye, Wheel of Fortune, Family Fortunes, Blockbusters, and The Weakest Link.
Mansur Khan, 53, of Pinner, north west London, said he loved Gladiators, but that Bullseye was his favourite gameshow.
The pharmacist said: “I loved the original Gladiators and the new one isn’t bad – but I miss Ulrika and John Fashanu.
“The greatest ever gameshow, however, without a doubt was Bullseye with Jim Bowen – I can watch that time and time again and always find it funny.”
A spokesman for Playcasino.com said: “Our research found that Gladiators is the UK’s most popular game show.”
Nathan Vega, of Playcasino.com, said: “Game shows are a huge hit with the UK public and continue to provide joy and healthy competition amongst the population.”