I guess it's time to search my bookshelves for other series of books that we're addicted to.
Patricia Cornwell: I've just started reading these - Post-Mortem, Body of Evidence... Kay Scarpetta is a very convincing character. I don't know anything about her job or the place she lives, but I do believe everything as I read it and find myself cringing in my chair as if I can smell things she doesn't even describe.
Dean Koontz: I like nearly all his books, and I guess they're mostly not series. But I really like Odd Thomas - different and yet with all the concerns of a "real" person negotiating the real world.
Tony Hillerman: He's another one who writes about a world I don't know. I started reading his books when I saw a kid in the school chess club with one, and I was quickly hooked. The locale attracted me, since I was living in Utah, and the characters intrigued me because they gave me a window to look into a different worldview. I felt like I was invited to see something new by friends who really want me to understand.
Michael Connelly: I couldn't get into these books at the start, though my husband really enjoyed them. Then I read Blood Work and I was hooked. I'm not sure what, if anything, changed in the writing - there's still lots of detail, lots of real locations (they're what drew my husband in). Maybe it's just that I care more about the character. I certainly wanted to see him survive and win.
Jim Butcher: He makes the unreal seem real, and he keeps me thinking and wondering, trying to relate his world to mine. Everything makes sense, just a different, weird and intricate sort of sense. My husband really appreciates books that stick to their own internal logic, and these do qualify.
So... be convincing, get the details right, keep it logical, make characters that people can care about, ... Sounds like good advice to me. And if I can set my stories somewhere interesting too, real or imaginary, I guess that'll be a bonus.
The bookshelf's still bulging, paperbacks two deep and two high on each level, with lots more series to explore. But perhaps I ought to get back to writing my own at some point.