I think they repeated it last year after Douglas Adams's death. To be honest I think the original radio series was a lot better. A lot of the ideas (like Zaphod's extra arm and head) just didn't work with the effects technology available at the time, and Sandra Dickinson was a tragic miscasting as Trillian
I haven't actually read all of the books. What you do have to bear in mind is that each version of the Guide is an entity in its own right. The TV series was not a straight adaptation of the radio series and the books are similar, and yet entirely different, to both. Most people have a preference for whichever they encountered first as they quite justifiably view that as the 'correct' version. I would definitely recommend getting hold of a copy of the radio series though.
I haven't actually read all of the books. What you do have to bear in mind is that each version of the Guide is an entity in its own right. The TV series was not a straight adaptation of the radio series and the books are similar, and yet entirely different, to both. Most people have a preference for whichever they encountered first as they quite justifiably view that as the 'correct' version. I would definitely recommend getting hold of a copy of the radio series though.