Surefire, Streamlight, and Inova
My Surefire 6P is great, but very expensive, short battery life, expensive batteries
My Inova XO3 is almost as good as the Surefire, uses an extremely bright LED bulb that is almost as bright and is far more energy efficient, so the batteries (same type as Surefire) last a lot longer (I haven't had to change them yet).
http://www.flashlightreviews.com/reviews/inova_xo3.htm
I also have an Inova X5, not as bright and shorter ranged, but small and handy, carry it in my pocket more often. I've changed the batteries once or twice since I bought it back in 2004
For general use, I can't recommend the Streamlight 3C LED enough. Ten LED bulbs light up a room very well, and it uses standard C-cell batteries (cheap and available almost everywhere, including your kitchen junk drawer). Battery life is 300 hours plus....I change the batteries in my two flashlights every couple years, and use them lots. However, it's a larger flashlight, not quite as big as a 3 battery Mag-Lite, but too big for mounting on a firearm.
http://www.amazon.com/Streamlight-3...BFS9/ref=sr_1_2?ie=UTF8&qid=1329066397&sr=8-2
All of these have been very reliable, and very good. Also have lots of cheap flashlights around the house, but the ones listed above are the ones I depend on most of the time.