YBYY is an excellent book for getting to the higher-up stuff. I think it fits in neatly with GTD, too, since after doing the mental heavy lifting (the first six or so exercises), you can make each of your 10 goals a project (or, if they're still a little lofty, the monthly version of each that Ditzler suggests) and GTD the hell out of it from there. It's also really methodical, which fans of GTD tend to like.

I know it's a little?okay, *very*?woo-woo, and some might say less methodical, but I also heartily recommend The Artist's Way, by Julia Cameron. Probably better for the designer geek than the coder geek, but there are good exercises (morning pages, or The Clearing of the Crap, as I like to call it) for everyone. Is Your Genius at Work is a great book for getting a handle on your Life Purpose, too, if it "speaks" to you (meaning, the exercises are great, but all of this stuff is intensely personal, so you need to find the Way In that works for you).

Someone who's really good at helping people figure out what they love to do highly recommended Now, Discover Your Strengths, which is more business-y. Marcus Buckingham, the author, works for Gallup, and they've got a StrengthsFinder thingy on the interweb you can access after you've read the book that's supposed to be great. (You have to buy a new copy, since it's one-number-per-customer.)

If you want to, of course, you can get all zen buddhist on this crap and make your own way. I mean, we're talking 50,000 feet here--it's uncharted territory! For example, you could meditate or take a walk every morning with the intention of figuring out what you really want. The important trick with this is to *let go* of the intention as you do your meditation or walk, and to do it really regularly: the same time every day, the same route if you walk. It's slow, but it works.