I had the complete THHGTHG on audio cassette, religiously recorded from Radio 4 every week.

What I like about the Guide is that every release (radio, books, TV series, films etc.) tell a different story (although the recent film was a complete travesty). Each revision of the books was also subtly different.

I taped the lot, then completely played them to death. I was enthralled by the whole thing.

Got the 6 BBC CDs somewhere. Must be 25 years old. Wonder if they'll still play.

There is, or at least there was, a book of the radio show scripts. Fascinating read - as well as the shows, there are pages of footnotes and annotations about how Adams came up with his ideas, the limitations of budget and studio facilities they had to work under and why Adams would repeatedly walk out of the bathroom with the scripts apparently typed on toilet paper.