Much as I like 'The Liar', I reckon 'Paperweight' for Stephen Fry's best book. This hefty but unputdownable volume collects a great tranche of Mr. Fry's reviews, essays, columns for (e.g.) 'The Listener' and (maybe best of the lot) 'radio essays' delivered by his professorial alter ego, Donald Trefusis. ('Paperweight' also contains his early play 'Latin!', which makes a truly eye-watering read decades after its first performance and is really not indicated reading for the easily offended.)
I don't think I can recommend this book highly enough - of course, Mr. Fry's wit and ear for parody never let him down, but then you'd maybe expect that. What might be more of a surprise is what an incisive commentator and critic he can be. Every topic Mr. Fry writes about is illuminated by his efforts - be it cricket, 'Clause 28', the Father Brown stories, Sherlock Holmes, socks, sex or Bernard Levin. Be careful how you use this volume though - once you open 'Paperweight', there's a fair chance the rest of the day will have to be given over to its perusal.