Battlefield Earth was my favorite book as a young teenager. Ignoring everything else about the author (which I didn't know at the time), I thought the book was brilliant (especially the first half). It touched my imagination in a way no other book had before, and I must have read it about a dozen times.
I seem to recall the book cover saying that a major motion picture was coming out soon, but I guess time is relative. For me it was about eighteen years (which was more than half my life at the time) before the movie actually came out, and that seemed like an eternity.
I wish I could say it was worth the wait. The movie was horrible -- it had bad acting, a bad script, and couldn't carry the book in only two hours.
It currently has a 3% tomatometer score at Rotten Tomatoes and a 2.5/10 at IMDB. The movie also won Worst Picture of the Decade at the 2010 Razzie Awards.