Dan Simmons Hyperion, anything that has "The Shrike stands roughly three meters in height and is described as being composed of razorwire, thorns, blades, and cutting edges, having fingers like scalpels and long, curved toe blades. It is basically a gigantic, bladed killing machine." as a baddy in it has to be cool:
http://en.wikipedia.org/wiki/The_Shrike
Oh, and Unto Leviathan by Richard Paul Russo (also known as Ship of Fools in the US) was quite terrifying but one of the best books I've ever read.
