The books were awesome and so was the original radio show. That "sixth novel" that came out in 2010 (by Eoin Colfer) was utter crap though. I understand that Adams' widow commissioned the thing and Colfer wanted it to be the best thing he ever wrote, but damn, was it uncomfortable to read...
i think something a little heavier the alcohol was being used when he wrote those books. buddy.
that dud had to be on lsd or something
same thing with the riverworld series as well, sometimes altered mindstates can make really great literature
other times you get bloody messages about zorbon stealing peoples left asscheeks written on the bathroom wall, try sending that in to your publisher