8NX...Not sure if the battery problems have been solved (do a search). Nice light, personally not a favorite, though.
M9, Good light. USes standard 3.6V battery stick. Very focused beam will outhrow most other lights, but suffers somewhat due to lack of flood qualities in the beam.
M11, similar to M9, full size light uses C size rechargeables in a stick. Pelican has changed the lamp in the lamp module to give it more floo qualities. I liked the older pin-point beam lamp better then the current one. To tell the difference, the newest lamps look larger and have a domed appearence. The older lamps were tear dropped shaped.
--dan