For me, have done a few times, but mostly local TV in the late 70s when I featured in the local tea-time news progs. (About Anglia and BBC Look East) with my main collecting hobby (I'm a terrible hoarder!) of antique newspapers and magazines.
From that I then did a spot on Anglia TV's "Bygones" (some might remember it!) with the delightful Dick Joice - also appearing on that show was a guy who collected antique guns and the de Jong sisters who amongst other things played piano in the silent film era. Fascinating to talk to them!
And one time the Beeb sent a film crew to my thatched cottage in the middle of nowhere to film me. There was a cameraman, sound recordist and the reporter was Christopher Lewis** who eventually became the executive producer of the Antiques Roadshow, which neatly segues...............
To my last appearance on TV (fame is a fickle mistress) was when I was on The Antiques Roadshow in the early 90s with my huge Victorian roll-top desk - the expert was Christopher Payne, but the surprise for me was when Christopher Lewis** remembered me and coming to film my collection of newspapers.