I still remember the first time I met Marvin. It was 15 March 1978 and the first broadcast of episode two of the Hitchhiker's Guide to the Galaxy radio series. From the moment I heard Stephen Moore's electronically modulated voice as Marvin, I was hooked, and he remains my favourite character in the show. Partly this has something to do with the surprise I felt, not just that a robot should have a personality of some sort but that it should be such a comically repellent one, marked by self-obsession, self-pity and hypochondria. Marvin plays no great role in the various narratives of the series (radio, book, film, etc.) but he is a great comic character in his own right.