Hard to pick just five:

1. Hyperion and the rest of the Hyperion Cantos series by Dan Simmons
   
2. Marooned in Realtime by Vernor Vinge (though everything else he's written could easily have taken this spot)
   
3. Altered Carbon by Richard K. Morgan (and any other Takeshi Kovacs novel)
   
4. Footfall by Larry Niven -- IMO the best he ever wrote
   
5. Childhood's End by Arthur C. Clarke
   

Other favorites:

• The City and the Stars by Arthur C. Clarke
  
• Accelerando by Charles Stross
  
• Pandora's Star and Judas Unchained by Peter F. Hamilton
  
• Iron Sunrise by Charles Stross
  
• Virtually anything by Robert J. Sawyer (particularly the "Neanderthal Parallax" trilogy)
  
• Snow Crash and Diamond Age by Neal Stephenson, though I'm with dag, everything that's followed has been disappointing
  
• Domesday Book by Connie Willis
  
• To Say Nothing of the Dog by Connie Willis
  
• The Golden Age Trilogy by John C. Wright
  
• Any short story by Michael Swanwick (particularly "The Radiant Doors" -- dft, there's another dystopia to be found in that one)
  

Oh, and I like Dune, Foundation, Harry Potter, Lord of the Rings, 1984, Brave New World, and Animal Farm too, but that almost goes without saying.

I do read politics too, but those aren't really very fun most of the time. Educational, but not fun.

I've read so many great books that it's really hard for me to whittle it down to five that I think are the best, so I'm going to go with the first five that come into my head. I'm guessing that the first five must have made the greatest impression on me, so it's a reasonable place to start a favorites list.

1. Slaughterhouse Five - Kurt Vonnegut. Vonnegut is probably the single most influential author to me. His protagonists and story lines always clicked with me. It was like he was writing them just for me.

2. Catch 22 - Joseph Heller. Everyone's heard of this one, and it's considered by many to be one of the best novels of the 20th century. If you haven't read it yet, put it next on your to-read list. Notice my first two novels are both set in World War II. I don't know if that means anything or not.

3. The Amazing Adventures of Kavalier & Clay - Michael Chabon. Considered by many to be Chabon's greatest work. I noticed you read one of his book's, dag. I think you owe it to yourself to read this one. I plan on reading The Yiddish Policemen's Union soon, because I've heard good things about it too.

4. The Trial - Franz Kafka. A dark novel, to say the least. To me it's about the absurdity of life and accepting fate. I don't believe in fate, but I sometimes wonder about the futility of existence. Can't help it.

5. The Foundation series - Isaac Asimov. Read the series when I was a teenager. The idea of being able to use science to not only predict but also control future events fascinated me, and that it was set in the future, complete with space travel, made it even more interesting. I liked how Asimov later was able to merge the Foundation series with the Robot series.

Other novels worthy of mention:

- Tropic Of Cancer - Henry Miller - Almost made the Top 5
- Life of Pi - Yann Martel
- Galapagos - Kurt Vonnegut
- Crime and Punishment - Fyodor Dostoevsky
- Breakfast Of Champions - Kurt Vonnegut
- 1984 - George Orwell
- Stranger in a Strange Land - Robert A. Heinlein
- God Knows - Joseph Heller
- Something Happened - Joseph Heller
- Ringworld - Larry Niven
- The Outsiders - S.E. Hinton

Larry Niven anyone?

Pandora's Star by Peter Hamilton
Ringworld by Larry Niven

Anyone see Sunlight? Great 2/3s of a sci-fi movie.
I can't wait for Ender's game...lets hope they do better casting on Ender than they did on Anakin, though.

Unfortunately, sci-fi movies nowadays seem to be more about special effects and explosions than story and characters. There are many books I would love to see made into movies, but I'd want them to be made exactly the way I envision them as I'm reading them. I'd hate to see how the movie industry would butcher some of my favorite books.

Oh, I thought of another old favorite (well... 1985). Larry Niven and Jerry Pournelle's "Footfall". Classic alien invasion.