I heard the radio series first. When I was still at school I used to make a point of staying up for the 11pm comedy on Radio 4. I'd always be half asleep by the time it came on.
Even so, there are a couple of series that really stuck with me - this being one of them and the other being The Sofa Of Time which seems to have disappeared without a trace
I really wanted to get the audio CD.
Anyway, I think The Boosh is amazing. I saw a trailer for the first series on BBC3 and thought "this is familiar - wait, it's THAT THING! Have to watch!" and gradually began introducing all my friends to it.
I've yet to see the live DVD but I hear excellent things about it. I just hope to ACTUALLY see them live soon at some point.
I love the way it's all so cheaply done in the TV series. It really adds to the comedy of it and adds to the way they break down the fourth wall. Like how the characters are in front of the curtain at the start talking directly to the audience then within the show are playing themselves and other characters (Fossil playing Death and going "I'm a cockney, I'm a cockney" from under his cowl springs to mind!) in a kind of play of recent events/events that never happened/we can never verify its truth! The radio series seems to be more "real".
I also think the TV series is somehow less wholesome than the radio series. On the radio, the evillest thing out there was Bob Fossil, and in his way even he was ultimately on the side of Vince and Howard. I think I prefer the more innocent version.