Stephen Fry asks unanswerable questions about body parts beginning with the letter H.

Sean Lock, David Mitchell, Danny Baker and Alan Davies are quizzed on hoaxes.

Stephen Fry asks unanswerable questions about happiness, with Andy Hamilton, Rich Hall, Phill Jupitus and Alan Davies.

Stephen Fry asks unanswerable questions about Halloween, with Chris Addison, Sean Lock, Dara Ó Briain and Alan Davies.

Stephen Fry asks unanswerable questions about horses and hunting, with Clare Balding, Dara Ó Briain, Jimmy Carr and Alan Davies.

Stephen Fry asks questions about hypnosis, hallucinations and hysteria. With Ronni Ancona, Phill Jupitus, Robert Webb and Alan Davies.

A compilation of some of the best bits from the H series of QI, with Stephen Fry, Alan Davies, and a host of special guests.

A compilation of some of the best bits from the H series of QI, with Stephen Fry, Alan Davies, and a host of special guests.

Stephen Fry and Alan Davies are joined by Jimmy Carr, Claudia O'Doherty and Suggs.

A compilation of some of the best bits from Series L.

More of the best bits from Series L.

Compilation from Series M, part 1.

Compilation from Series M, part 2.

A compilation of some of the best bits from Series N, with Sandi Toksvig and Alan Davies.

More of the best bits from Series N, with Sandi Toksvig, Alan Davies and guests.

A compilation of some of the best bits from Series O, with Sandi Toksvig and Alan Davies.

More of the best bits from Series O, with Sandi Toksvig, Alan Davies and guests.

Sandi and Alan poke holes in the patchwork with Sally Philips, Jimmy Carr and Gyles Brandreth.

Sandi Toksvig looks at pathology with Sindhu Vee, Rhod Gilbert, Ed Byrne and Alan Davies.

Very Greatest: Compilation from series P - Part One.

Very Greatest: Compilation from series P - Part Two.

Sandi Toksvig looks at some quirky questions with Alan Davies, Loyiso Gola, Jason Manford and Sarah Millican.

A selection of the best moments from the Q series of QI, hosted by Sandi Toksvig with Alan Davies and their guests.

Another selection of the best moments from the Q series of QI, hosted by Sandi Toksvig, with Alan Davies and their guests.

Sandi Toksvig examines some revolutionary ideas with Alan Davies, Gyles Brandreth, Susan Calman and Jessica Fostekew.