Here are a few tracks based on that most famous of comic sc-fi series, the Hitch Hikers Guide to the Galaxy. I'm still hunting around for more tunes, so do let me know if you have any!

'Journey of the Sorcerer' (6.06MB) (MP3)
The original tune by The Eagles, used in shortened form for the radio series, and in edited form for the TV series.
'Hitch Hikers Remix' (483KB) (S3M)
A popular remix of the main segment to the above tune.
'Hitch Hikers MIDI Remix' (15KB) (MID)
A one-off MIDI rendition I found, with a very slow, but full beat.

I've also got the four Marvin the Paranoid Android songs for you, to be found here.