Eamonn Holmes and Michael Aspel are among the bookmakers' favourites to take over as presenter of TV quiz Countdown when Des Lynam quits.
Betfair has Holmes as the most likely replacement at 5/1, while Paddy Power makes Aspel its 6/1 favourite.
Tom O'Connor and Gyles Brandreth, regulars on Channel 4's long-running quiz, are also tipped by bookmakers.
But Lynam's co-host Carol Vorderman - rated as 3/1 by William Hill - has said she does not want his job.
She said: "Please don't put a bet on me as I'm really not going to be the new host of Countdown. Save your money.
"But it's exciting to see so many names have shown interest in taking on the role because as far as I'm concerned it's one of the best two jobs in television, mine being the other one."
Deal or No Deal host Noel Edmonds is also in the running, while Paul Merton - one of the team captains on news quiz Have I Got News For You - is listed at odds of between 10/1 and 16/1 by the three companies.
However, veteran chat show presenter Des O'Connor was also proving popular, William Hill spokesman Rupert Adams said.
TOP TIPS FOR COUNTDOWN
Betfair: Eamonn Holmes (5/1), Carol Vorderman (pictured, 8/1), Noel Edmonds (9/1)
Paddy Power: Michael Aspel (6/1), Eamonn Holmes (8/1), Paul Merton (10/1)
William Hill: Carol Vorderman (3/1), Noel Edmonds (8/1), Jo Brand (10/1)
Most of the bets the bookmaker took on Sunday were for Vorderman but there were more for O'Connor on Monday, he said.
"The wagers are from all over the country, so there could well be something in the rumour," Mr Adams added.
Over at Paddy Power, spokesman Darren Haines said that "early punters believe Michael Aspel has the familiarity and gentle appeal for Countdown's older audience".
But he added Merton had been "well backed" last year when Channel 4 was searching for a presenter to replace the late Richard Whiteley, who was with the programme for 23 years.
Merton's ability "to bring humour whilst hitting the right tone" would prove popular again, Mr Haines predicted.
Other figures on the bookmakers' lists include comedians Jo Brand and Angus Deayton, along with established presenters Phillip Schofield, Alan Titchmarsh and Terry Wogan.
There are some long shots as well, such as Prime Minister Tony Blair, at 500/1 with William Hill and Paddy Power, and eccentric rocker Ozzy Osbourne, whom William Hill list at 200/1.
Lynam, 64, has said that he will leave Countdown at Christmas, having taken over last October.
Holmes (R) was host of the BBC's Star Spell, won by Whiteley in 2004
He confirmed on Saturday that he was tired of the 250-mile journey from his home in Worthing, West Sussex.
The former sports presenter has been recording five shows each week at studios in Leeds.
The search for a host "is still on", a Channel 4 spokeswoman told the BBC News website.
"No decision has been taken," she said.