Who is the greatest tv quiz show host ever?

Allsorts

University Challenge, Magnus Magnusson, for light entertainment I think Terry Wogan.

I don’t think Magnus Magnusson ever chaired University Challenge. It was Mastermind.
The original UC question master was Bamber Gascoigne.

Magnus Magnuson and Terry Wogan

Not everyone's cup of tea, but I've always liked Jimmy Tarbuck (he hosted a game show called Winner Takes All.) He really made me chuckle. For the more serious quiz, then Magnus Magnusson on Mastermind.

University Challenge, Magnus Magnusson, for light entertainment I think Terry Wogan.

Only joking. It does rather depend on the type of quiz show. Bruce Forsyth would not have been ideal for University Challenge.

Bamber Gascoigne.

Robert Robinson

Bob Monkhouse or Terry Wogan

Bruce Forsythe

Richard Osman

Terry Wogan on Blankety Blank.

Magnus Magnusson

Bruce Forsythe