Focusworks E2. Modified it with a new reflector, Nichia 519a, 4500k tint, and programmable firmware. Love the fact that it has got to be the easiest to modifify light I own, and Focusworks finishing of the body is on par with any of my customs.
Probably my Ultratac A3 modded with 4000k 519a. Great light and pretty bright on a 14500. For non-production lights I have a FM 18500 body running an omnivore drop in but the driver is only alright (convoy 12 mode). Would like a driver that can fully utilize the li-ion cells while also being able to handle AA and NiMH as well.
Close second would be Thrunite TH20 with your choice of 3535 led. I have one with a 3500k LH351D and one with a 4000k 219B. Both are great but they have been relegated to backup status as they compete with a Wizard Nichia and a Emisar DW4 headlamps.