A great story and characters will suck me in every time, no matter the genre. But I do have a weakness for PNR, SF, UF and I'll melt completely if you throw in some humour and a breathless romance.
Threw this one on the dnf pile - just got bored. Everyone was so busy THINKING (invariably at odds with the other character) instead of doing that this book felt a little juvenile, and terribly obvious in what was going/had to happen next.