Sometimes there just isn't much to say about a book/movie comparison. So here's an abbreviated seek the original of:
The Hitchhiker's Guide to the Galaxy
(book by Douglas Adams. Series: 1981. Movie: 2005)
There should be so much to say about this book (series). But... as much as I love it, I have little to say. It's great! The universe is the rabbit hole filled with ridiculous and thus plausible ideas and observations about life, the universe, and everything. It’s a series following characters trying to find the meaning of life... well, okay, they don’t try, they just stumble into the journey. The kicker is that as improbable as the ideas are, they’re strangely believable. Kinda like a yeah, that would be just our luck sort of believability. Dramatic alien invasions go unnoticed, Earth has a purpose after all and then it’s destroyed for a completely bureaucratic reason, and the answers to the mysteries of the universe are common knowledge to everyone but us.
The 2005 film version, however, does very little with that. Instead of being about the meaning of life, it focuses mostly on the romance between Arthur and Trillian. This is barely touched on in the book, and it was all right as is because the book was never meant to be a romance. The movie is about the wrong thing! It should've been about the meaning of life, bureaucracy and what a dumb place the universe is, not Arthur hooking up with Trillian!
But everything else about the movie is perfect! Mos Def nailed the role of Ford, Zooey Deschanel is perfect as Trillian, Sam Rockwell is ideal as Zaphod, and Martin Freeman is absolutely PERFECT as Arthur Dent. Stephen Fry is SO GOOD as the voice of the Guide I can't imagine anyone else performing it now. And the Vogons! I never had a clear picture of the Vogons when reading the book, but when I saw the movie I thought yup, those are Vogons. I have never pictured them any other way since.
Really, the humor is spot on, the action is funny, the guide is funny, the story is good enough for what it is. I wish it had done more with the meaning of life motif, but even so it's still faithful to the spirit of the humor in Adams's book.
What about the '81 TV series? It's... cult. Made on a budget of nothing, it takes a lot of getting used to. But they tried, and it is much more faithful to the book, following it almost step by step, even covering the events in the second book as well, The Restaurant at the End of the Universe. I wish this series had been remade with the casting and production values of the 2005 film. It's a decent viewing if you wanna have some laughs at the cheesy special effects.