I love Asimov, and Scattered bodies go (and the sequels) by PJ Farmer are great. He is an amazing author. Heinlein is still my favourite SF author. Also PK Dick, and anyone really wanting a good SF read try and find some Cordwainer Smith, amazing. I have many thousands of SF books (I HATE Fantasy btw). Prefer up to 70's, anything newer I rarely read, except the later Heinleins etc.
Shame they rarely make good SF films