Well, this will open a can of worms

I know that there are several different requirements that one could use to define their "best flashlight", but I've settled on a few that I like to see in a daily use light...either backpacking/camping, combat zone in Iraq or daily use around the house or office.
First, I think the LED is a no-brainer. They are just inherently more robust than most incandescent lights. Second, they are much more efficient hence giving you longer run times. Additionally most of the regulated LED's give you options for output...very handy for a number of scenarios. Now for size, that's quite subjective, but most could easily EDC a single 123-3V, AA or AAA LED in their pocket or on their belt; so when I hear small, that's what I focus on. I do have a Gladius Night-Ops (sounds "tactical-stupid") which I've had the LED upgraded, and it's absolutely awesome...several levels of output and functions making it a very versatile light, but a little too bulky for daily wear (it is in my duty bag though).
So for "best small flashlight" categories, here's what I've concluded:
Best Keychain LED: Inova's Microlight or Photon
Best single AAA LED: ARC or Fenix POD
Best single AA LED: Fenix L1D
Best single 123 LED: Novatac's 120 EDC
Best single 123 LED deal: Either the Fenix P2D or P1D
Best "emergency" LED (for the kid's/wife's bags): PAL LED (9V)
Best small headlamp? Well, I like the Petzl Tikka Plus variations and I also like the Princeton-Tec EOS as well...both are 3xAAA. A headlamp is a great option for hands-free work...changing a flat tire, getting the coffee going early in the morning while camping or reading a book in the tent at night.
There are a ton of 6V (2x123 battery) LED's on the market, it's hard to choose. Most just want a good "emergency" light and I think the new Surefire G2 LED is a great bargain, but it only gives you and on/off function and I still like the ability to select output levels. Surefire's L2 (don't have the new L1 yet), is a good option of high/low output...you don't need 5000 lumen output for everything, especially if you're just digging around in your pack or locating your keys on your nightstand.
I like the comparison of Novatac to Busse. Novatac's are built as tough as Surefire's but they have much more functionality.
ROCK6