I have some surefire G2 nitrolon LED's and a streamlight polytac, which is very similar.
Both are good, Streamlight is better and about half the price. They both use the pricey 123 batteries, but since they are LED, they last quite awhile.
The Pelican 2360 is very hard to beat. It uses AA's and has a metal case and is just as bright as the above two. I personally prefer the plastic bodied ones but I prefer replacing the AA's over the 123's.
There are much higher priced flashlights than those, but they seem to work well for me and all of them are better than any flashlight made 10 years ago.