What I like in listening to Charlie's show, or such other mavericks down the years as Alexis Korner, John Peel and Andy Kershaw, is to hear new sounds, interesting informed-but-personal-opinions, mixed in with relevant classic oldies. I want a DJ who is unafraid to get excited about some connection that he makes whilst perusing his CD / record shelves and then communicates this to me. I don't want him to be constrained by a producer or programme controller's playlists.
While all those names would be in my top ten, I've never thought of them as particularly 'maverick' but of course they've all been fortunate enough to work for the BBC and get slots outside the mainstream where they've been more or less allowed to play what they like.
In fact I think for long periods radio was more influential in forming my tastes than anything else (and ruining my sleeping habits for ever with all that late night under the covers listening as a teenager). Certainly in the case of jazz, where Humph and Peter Clayton on the BBC and Willis Conover on Voice of America where instrumental in me discovering so much.
Generally it's been the BBC with its no ads public service remit to which I've usually turned, though as a kid the pirates (in my locality Radio Caroline North) were more listened to than anything else, with DJs like Tony Prince playing lots of soul and Don Allen's Saturday night programme attuning my ears to country music.
Bringing things up to date it seems Mark Lamarr gets all the kudos. He's good, but I like Stuart Maconie a lot as well. And, switching genres, Russell Davies's classic song show on Sundays is a model of informed, witty old style BBC presenting. And believe it or not, Brian Matthew and David Jacobs are still going (though sadly Jacobs soothingly unctuous tones have now turned into something of a croak, or they had the last time I heard him.)
And the BBC local stations have had some brilliant presenters. Steve Voce did a great jazz programme on BBC Merseyside for many years, Stuart Colman on BBC London on Sunday lunchtimes, and Dr Rock on BBC York.
Anyone else you'd care to mention?