they all pale in comparison to Robert Heinlein, Isaac Asimov, Arthur C. Clarke, H. Beam Piper or Frederic Brown. Hell! They pale... 
PERIOD!
Call me an old fashioned snob... 
but I'll be double dipped in flatcat poop before I am going to pay $8.99 for a new sci-fi paperback I'll not enjoy when I can reread the Gold Age Sci-Fi Classics from my local half-price book store for from 50 cents to $3.
BTW in the 10 cent bin I found 14 paperbacks for this coming week, one is Asimov's The Martian Way which I haven't read in probably 15 years!