After considering this one a bit more, I think I feel certain enough to rate it. It was a decent book, perhaps even a good book, but its particular brand of incongruous humor isn't quite my taste, and the whole plot seems to be a setup for the books to come (which I don't plan to read at the moment). Still, I found Arthur to be a compelling protagonist, and the opening few chapters were some of the best I've read in a while. And Zaphod was very interesting; I imagine his backstory would be great fun to discover (if I ever come back and read the other books).

Also, though it may be horrifying to many, I liked the movie better. With the exception of Zaphod, I found the characters to be mostly true to their book personalities (Martin Freeman was perfect), and I actually liked the changes to the plot, because it became a cohesive, coherent whole instead of a fragmented collection of scenes leading to a grand inciting incident at the end. Do read the book first, but I think the movie's well worth watching.