Sci-fi is such a broad genre in both literature and film. Some of my favourite sci-fi novels are a bit more "near-future" and Earth-bound instead of the vast sweeping space fantasy from the likes of Arthur C. Clarke (although I enjoy his work as well).

Obviously I enjoy things like The Sprawl Trilogy and Snow Crash, but a few less obvious examples are:

• The Laundry Series by Charles Stross - James Bond meets Lovecraft
  
• When Sysadmins Rules the Earth by Cory Doctorow - after the Apocolypse, who keeps the internet running?
  
• Jurassic Park by Michael Crichton - dinosaurs... 'nuff said.
  

Here are a couple of movie recommendations as well:

• "One Point O" or "Paranoia 1.0" (2004) - a cyberpunk story of subliminal advertising and paranoia
  
• "Dark City" (1998) - a neo-noir film with themes of memory loss and the nature of human identity