For LED, right now it's probably a homebrew Luxeon Star unit called the Hydra. Four 1.2W Luxeons, four DC-DC inverters, all crammed gracefully into a 2-D sized Mag-Lite.
Commercial product: The Tektite Trek 6000 EX60 and Trek 400 EX40 run neck and neck as being the brightest LED flashlights available without having to home-brew.
If you don't mind a very wide-angle flood, the Inretech Super6 would be in the running when it comes to maximum total emitted flux. Six underdriven (for efficiency) 1.2W Luxeons in a 3-D Mag-Lite body. Rumor is they're fine-tuning the resistive elements to make it even brighter.
A homebrew that was recently built using a single 5W green Luxeon in a Surefire casing (original Surefire model not yet known) could change everything though. It should literally blow everything else clean out of the toilet. I should know in a few more days just how far that light creams all the others.
For incandescent, I don't know. A number of Surefire models probably stomp everything else flat. Brightest Surefire I've ever seen is the E2, and that's just a baby compared to their larger lights.
For an incandescent that's cheap and easy to feed, the Princeton Tec Surge is probably the brightest flashlight on the lower-end consumer market; it feeds from ordinary AA cells.
Same with HID. Don't know much about what's available. Surefire has a couple that probably whack all the others silly. I've only seen one HID, and that's the UK Light Cannon 100. Available for under $150 in dive shops.
Chainsaw maker McCullough has a very high-end HID available that would put a Light Cannon to shame.