The Merchant Princes series: It's like Amber, but it's sci-fi masquerading as fantasy instead of the other way around. It's like A Song of Ice and Fire crashing into The Sum of All Fears, except with more likeable characters and less horrible politics. It's really, really good science fiction.

The Traders' War in particular is a bit of an uneven book that takes a while to get going - but once it gets its groove on, it's thrilling, surprising and immensely satisfying. The plot may not play quite as fair as most of Stross' stories: there are several amazing coincidences and last-minute miraculous escapes, but you really just have to take them in stride. I would love to give this one full five stars, but it does drag a bit, and ends on a bit of a cliffhanger. At least you don't have to wait ten years for the sequel.