Even though DNA started out as a science fiction writer I think this is his best work yet. The subject is rather depression (traveling around the world to visit endangered animals), but he manages to write a very funny yet informative book about it.

An absolute MUST for anybody interested in nature and who enjoys a good story.

 Join Douglas Adams's hapless hero Arthur Dent as he travels the galaxy with his intrepid pal Ford Prefect, getting into horrible messes and generally wreaking  hilarious havoc. Dent is grabbed from Earth moments before a cosmic construction team obliterates the planet to build a freeway. You'll never read funnier  science fiction; Adams is a master of intelligent satire, barbed wit, and  comedic dialogue. The Hitchhiker's Guide is rich in comedic detail and  thought-provoking situations and stands up to multiple reads. Required reading for science fiction fans, this book (and its follow-ups) is also sure to please  fans of Monty Python, Terry Pratchett's Discworld series, and British sitcoms.
 

In the beginning, The Hitchhiker's Giude to the Galaxy was written. This made a  lot of people happy and is generally regarded as a good move.

Some time later, it was followed up (by a sequel). This also made a few  people ("The people...the things..." "The things are also  people," hissed Ford. "The people...the...other people...") very  pleased. I am among them. DNA is an excellent writer and this book is perfect alone, after its predecessor, or with a Pan Galactic Gargle Blaster. Brilliant  satire, wonderful characters, and the depressed droning of our favourite  Paranoid Android all contribute beautifully to a work of sheer unadultered weirdness. I'd reccomend reading HHGG first to all newcomers to the HHGG trilogy, but if you've already read the first in the series the best way to  follow it up is by reading the second. Or by stopping for lunch at  Milliways--The Restaurant at the End of the Universe! (But don't forget your  towel!)
 

 The White Robots of Krikkit sound a lot like the stormtroopers from Star Wars,  but it's probably better to compare then directly with the Nazis from which  those stormtroopers themselves were in all likelihood derived. The theme is of  how most people from the planet Krikkit want to enjoy life, listen to music,  have their own little farm to raise a family on, etc, while the warlords that  run their government are constantly trying to get them fanatically worked up to go forth and conquer the universe. Trillian gets some of her first real  character development in the whole series, or at least a few solid lines, when she is the one to piece this simple fact together, along with some other, less  simple facts. Again, a very cool book, and one which makes you think in a good  way about some really important stuff.

 The love story is touching and incredibly realistic, while of course still and  always narrated in this weird, delightful, illogical---or may be too logical for  literature---funny D.G.'s free wild style. But most of all, there is a real overall meaning. Whereas 42 means nothing, God's last message to His creation  bears a genuine message of tolerance and encouragement to keep satisfied with life and all that comes with it. The allegory of the otter pulling the raft is  deep and couldn't explain it best. The laughters of Prax about Arthur illustrates simply how ludicrous can be the metaphysical wonders. This last book  is full of metaphors like these

 I thoroughly recommend “Mostly Harmless”¦ Douglas Adams takes great delight in  driving each carefully crafted nail in to the coffin of the hitch hiker series. My only complaint was that it was too short. Enjoy Arthur one last time, as I don’t think your going to get another chance.