Double Star
Like many people, I go way, way back with Heinlein.  My very favorite book (and one that stands out in my mind--and with much affection--to this day) is Tunnel in the Sky.  I really, really wanted to go off to explore new worlds with a covered wagon and horses, like the hero does at the very end of the book.  But one of the nice things about Robert Heinlein is that he's got something for everyone.  One of my best friends has a different favorite:  Podkayne of Mars.  Go figure.                        --Shelly Shapiro, Executive Editor