OK - those are strong words, and there really has been a lot of great writing in the last 50 years (I did say "possibly"). But the combination of imaginative genius, over-the-top humor and just enough philosophical thought makes H2G2 a true standout. The radio plays predated the published books, and were my first exposure to Douglas Adams in the early 1980s - they remain the best way to experience The Hitchhiker's Guide.
There are only a few audio books that I return to and listen a second time. H2G2 is an audio book that I am moved to listen to at least every two years. Basically, I'd be lost without the Guide... If I could give it six stars, I would.
P.S. Years after I fell in love with the books, I learned that Adams had been a script writer and editor for the BBC's Doctor Who, and that he was a friend of Richard Dawkins - he introduced Lalla Ward (who played Romana on Doctor Who) to Dawkins, they subsequently married. Lalla Ward co-narrates Dawkins' audio books, which I also recommend. That serves to illustrate "the interconnectedness of all all things" (which is something you'll come upon in another of Adams' books - Dirk Gently's Holistic Detective Agency.
See my review of "The Primary Phase" for my glowing - nay, gushing - endorsement of the H2G2 radio plays.
This radio series starts at the offices of the Hitchhiker's Guide, where something is definitely amiss, and ends with a visit to the ruler of the universe - an old man, who's trying to feed his cat a bit of fish. It's as wild a ride as the Primary Phase, and was broadcast beginning in December, 1978 (months after the Primary Phase had been broadcast).
Really great stuff!
The series as a whole is a gem of British laugh out loud humour. This season in particular is notable for ending with a cliff hanger with all letters of the alphabet used. The actors, all of whom are major stars in their own right, have a rapport and timing worthy of all the awards they and this series have garnered. MJN airline has it all...16 seats rarely all occupied ...unless you count the possibilities of Otters on board...a steward who is absolutely brilliant at playing Yellow Car, two pilots whose conversations are a hoot and an owner who does her best to keep it all under control (good luck with that). A highly addictive series. The world needs more of this.