The "honourable" Dr Simon Mayo (he has a doctorate, but it is from the University of Made It Up).
Simon Andrew Hicks Mayo (born 21 September 1958, Southgate, London) is an English radio presenter who has worked for BBC Radio since 1981. As of January 2010, Mayo is presenter of Simon Mayo Drivetime on BBC Radio 2 and, with Mark Kermode, presenter of Kermode and Mayo's Film Review on BBC Radio 5 Live. In 2008, Mayo was recognised as the "radio broadcaster of the year" at the 34th annual Broadcasting Press Guild Awards and the "Speech Broadcaster of the Year" at the Sony Radio Academy Awards, receiving the latter for his "ability to paint colourful pictures of location and event and his ability to bring the very best out of his guests, encouraging conversation and interaction between them while skilfully nudging and controlling them" and for being "a master of light and shade, handling serious and lighter issues with aplomb."
His affability was picked out by the writers of The Thick Of It in their episode based around the inner workings of 5 Live - Nicola Murray MP complaining about her treatment at Mayo's hands, and being reassured that there had to be one person Mayo didn't like. Interestingly, no-one remembers this, whereas the thing about Mark's Flappy Hands ("God Kermode, your hands are massive" - Ollie Reeder) has stuck ever since. (Actually, of course, there have been many people Simon has not gone on with - Naomi Watts and Michael Stich to name but two).
Often Simon will wear a T-shirt with the name of a band on while broadcasting, in contrast to Mark's being invariably in suit and tie. Simon is particularly fond of his Born Again Floozies one.
For more info see here.