Surefire C3 or 9P with stock P90 lamp assembly. (If I have to choose between the two, incan is more useful than LED in environments in which I'd be most likely to need a flashlight.) I can run 3x CR123A cells or 2x 17500 rechargeable cells with similar runtimes. It throws well, provides adequate spill (a diffuser can be used for flood, if necessary), and renders colors correctly. The form factor is about perfect; it's small enough to easily carry, while being large enough to fit comfortably in the hand in a variety of orientations.