The Vorkosigan Saga by Lois McMaster Bujold
Oh, how I love these books. They're fun science fiction adventures, but way better than average. Bujold has a sense for the vulnerable hero; in the terrifying situations of science fiction, her characters are terrified. You think to yourself, "Yeah, that's what I'd be feeling if I was in that situation." And while dealing with their despair, doubt, fear and weakness, the characters rise to great heights; not with ease, but with difficulty. They're flawed, they make mistakes, but they're good. That's why it's so easy to love them.
This is a great series to sink yourself into. There are a lot of books, and they're all fun. Start with the two-book compilation "Cordelia's Honor." Yeah, I know it looks and sounds like a trashy romance novel, but it isn't. Trust me.