Of the so-called Juveniles, Citizen of the Galaxy is absolutely representative of the finest science fiction. Great storyline, memorable characters, and even a grain or two of morality thrown in. Of the ones you didn't mention, a fave of mine is The Rolling Stones.

The Rolling Stones is another good one. I like the little shop the boys open out there in the asteroid belt, Flatcat Alley was the name, I believe. Plus, the Grandma is awesome.

One of the most fun Heinlein reads that I don't often see mentioned is Glory Road. As for the most influential novel, I'm afraid it's a draw between Starship Troopers as a very young man (the idea of a personal responsibility to a group ethos - in a word, citizenship) and Farnham's Freehold as I've grown older (intellectual independence guided by personal integrity). I don't remember which of the juvenile's it was, but the one with the Space Academy students crashing on Venus has a recurring scene of deceased "heros" being included in all musters by someone answering, "I answer for him", has always struck me as being a custom worthy of serious consideration.

I liked Friday and To Sail Beyond the Sunset. The Man Who Sold the Moon is another good one.

My first two Heinlein novels were also my first two science fiction novels: Starship Troopers and Farmer in the Sky. Actually there was a third in there, Asimov's I, Robot. They were a Christmas present from my uncle when I was six or seven or so; he asked what kind of books I liked, and I said, 'science fiction', mainly as I'd just discovered Star Trek. My uncle was quite pleased to here that as he was an SF fanatic too.

Starship Troopers is still one of the most influential SF books I've ever read. In part this is probably because, when he gave the books to me, they came with strict instructions to my mother not to let me read Starship Troopers until I was older as it would mess with my head. Which pretty much guaranteed that it would be the first one I read ... and the one I came back to, time and again, as I was growing up.

Citizen of the Galaxy was my first RAH too. But it isn't my favourite. That would be Friday.

As I wrote on my blog I feel that Friday is much under appreciated.

http://www.di2.nu/200707/07.htm

For the first 10 years of my life I read nothing, but comic books and stories about baseball (I was and still am a baseball addict). But on my 10th birthday an older brother presented me with Harlen Ellison's Dangerous Visions and Robert Heinlein's Stranger in a Strange Land.

I never made it through Dangerous Visions, but I read Stranger in a Strange Land cover to cover and was hooked on science fiction. I think my mother was so relieved that I was no longer interested in comic books that she was more than happy to sign me up to the Science Fiction Book Club.

Heinlein opened my eyes to a new frontier of story telling and I never looked back. I quickly moved on to Asimov's Foundation series and the other great masters.

Ironically it wasn't until I grew up that I went back and read his earlier "juvenile" works.

Star Cadet was the name of the book where they crashland on Venus and are saved by maple syrup, as I recall. It was my first Heinlein book, and one of my first Sci Fi books. I was hooked! I reread Starship Troopers at least once a year, and really need to replace my copy of the Moon is a Harsh Mistress-it's worn out.

Gosh, there are so many good Heinlein novels. One that I haven't seen mention here is Tunnel in the Sky. Great riffs on politics and survival training. Yes, Citizen of the Galaxy is one of the best. I actually liked how it ended. Our society is very complicated, and corporate owners are constrained - very perceptive.

For sheer imaginative delight, the short story, Menace From Earth, was wonderful. Flying in giant caverns on (in) the moon! Now that's a good reason to start a moon colony!