Kindle Owners Lending Library Recommendations?

Hi everyone, I'm guessing that most of you readers are familiar with the Kindle Owners Lending Library for Amazon Prime members (one free book per month from a selection of Prime ebooks). I just finished reading Kurt Vonnegut's 'Sirens of Titan' via this program (great book!) but I'm having trouble finding anything else interesting to read from the selection of free Prime books. Any recommendations of worthwhile books available this way? I like science fiction most but am open to anything good. Thanks!