I met Heinlein after 'The Forever War' had won the Hugo and Nebula Awards. He shook my hand and said he loved the book so much, he'd read it three times.
We do a hard fantasy as well as hard science fiction, and I think I probably single-handedly recreated military science fiction. It was dead before I started working in it.
I love 'Starship Troopers.' I've seen it ten times.
I enjoyed Old Man's War immensely. A space war story with fast action, vivid characters, moral complexity and cool speculative physics, set in a future you almost want to live into, and a universe you sincerely hope you don't live in already.
Jack Campbell's dazzling new series is military science fiction at its best. Not only does he tell a yarn of great adventure and action, but he also develops the characters with satisfying depth. I thoroughly enjoyed this rip-roaring read, and I can hardly wait for the next book.
When I first encountered the 'Sigma Force' novels - long before I became friends with Jim Rollins - a bookseller told me that these stories were about 'geeks with guns.' While not entirely accurate, that's pretty close to the mark, and that really speaks to me.
If you want a favorite book, Orson Scott Card's 'Ender's Game'. You'll be hooked. I think he's written like twelve or thirteen.
All of the other books in the series... none of them are particularly like 'Ender's Game.'
Robert A. Heinlein has been an idol to me for more than 20 years. He can do no wrong, no matter how much he loves wars and hates pacifists.
For pleasure, I'll read military sf, or Elmore Leonard capers, anything that's fast and fun. Otherwise, I mostly pick at books, without any clear focus.