Right now, I'm reading volume two of William Patterson's brilliant biography of Heinlein. It's taking a while, as I have to go reread books he mentions, with a new outlook on what was happening when RAH wrote them.
My favorite Heinlein is generally the one I'm (re)reading at any given moment. I cut my teeth on his juveniles, and I'm especially fond of TUNNEL IN THE SKY and HAVE SPACE SUIT-WILL TRAVEL, though BETWEEN PLANETS is especially good as well because, really, who could not love that delicious Venusian dragon, Sir Isaac Newton? Who reappeared, by the way, in THE NUMBER OF THE BEAST. Huzzah!
Currently, I'm rereading THE PUPPET MASTERS for the gazillionth time. Not a juvenile by any means, though it came out during the 1950s when most of his boys' books were published. A dark invasion story, later
ripped off reimagined by lots of other authors,
but none of them have, to me, quite matched RAH's particular vision. The movie
based on it—though, really, lots of other movies have been based on it in so
many, many ways—which was released in 1994 and starred Donald Sutherland,
eminently drool-worthy, Eric Thal and Julie Warner, was a pale reimagining of
Quick aside: why has there never been a good movie based on a Heinlein work? No, not STARSHIP TROOPERS, though I loved its take-no-bug-prisoners attitude.
In THE PUPPET MASTERS, the Earth is invaded by slugs from Titan—or were they?—who attach themselves to humans by some delightfully squishy means and totally control their actions, though the humans are aware and screaming silently for help inside. A stalwart secret agent, working for the Old Man and his super secret agency, gets involved in the slug fight, falls in love with another agent, and deals with daddy issues, all while fighting this nasty invasion. The USA gets swarmed, and we don't even want to mention those behind the Iron Curtain—or, as Sam-the-agent asks in the book 'How would we know?' when the discussion of whether they were invaded as well comes up.
To me, the book succeeds on so many levels. Danger, adventure, sex, violence, pain, joy, love, hate, fear. Read it yourself if you don't believe me. Every time I read it, I find new things to like about it.