Re: 2 choices in marriage
Starship Troopers was his best, followed by The Moon is a Harsh Mistress - (of course in my opinion).
As far as Lazarus Long's marriage philosophy, I don't think I will take that advice from a guy who had his mom, and his two cloned daughters. Still a hilarious and awesome character, just really weird when it came to sex - he'd do it with a toaster if it had legs (in fact, Heinlein did have one of his characters do it with a toaster...excuse me, "grokked" it).
In any case, to the subject at hand, I'm envious of all of you who are happily married, and hope someday to join the club. The challenge is finding someone who, at the end of the day, makes you not care if you're wrong or right.
edit to add: of course, with all things, TANSTAAFL