Kim Stanley Robinson, 1993
One of the more famous books I've read in the last few years. Red Mars is the first book in a trilogy (Green Mars and Blue Mars are books II and III, respectively), but it stands alone as a complete story in my mind. Actually, it's so big, and so detailed, and covers so much literary ground, that it could probably survive getting subdivided into two separate books.
The format of the books is unique among science fiction books I've read - actually, it's unique among all fiction I've read, as far as I can tell. The book is divided into eight parts, each told from the point of view of a different main character. This results in each of the eight most important characters getting their turn in the spotlight, with their thoughts, emotions, motivations, and secrets described to the reader over a few tens of pages, then returning to the background for the rest of the story. Characters described in early parts are strangely well-known when they re-appear in later parts. Several years of story time may have passed since the reader knew this person so well, and the story does include characters aging and changing through time - none of the main characters are at all one-dimensional or static. Secondary characters, that are never dissected, are not one-dimensional, either.
There are many reviews of this award-winning book (and the whole trilogy) available on the web, so I'm not going to go into much detail here. Most of these reviews are very positive, but I found one that is quite negative. It's an interesting read, if only because the viewpoint expressed is so different from my own - I found it very easy to care about the characters, for example, and I really enjoyed the great descriptive detail about the surface features of Mars. The planet is almost elevated to the level of a character in its own right.
I would have liked a few more helper notes inside the front cover - a list of names of the First Hundred, and a larger and more detailed surface map of the planet (that included the polar regions) would have made the read a little nicer. Otherwise, I think this is a great book, and I highly recommend it.