I used to have a SureFire, but the TSA was kind enough to remove that from my bag on a trip, along with a Gerber tool.
Anyway, issue I had with the SureFire was the (at the time) odd batteries. Used to be a bit difficult to find the 123 batteries on the road. I could pre-order them, but it was expensive at the time.
Since the TSA was kind enough to relieve me of that awful burden, I've since kept my flashlights either fully rechargeable without needing to remove the battery or something that takes off the shelf, easy to find batteries. Specifically anything I can pick up at a 7-11, liquor store, or other late night establishment, has become my preferred choice.
I keep a Streamlight Vulcan in my work truck, but it's the older incandescent model.
I use the AA LED Streamlight plastic lights for most stuff. Bright enough for what I do, plastic so if I drop it into something at work, I don't have to worry about it vaporizing.
In my tool bag I keep a Streamlight 3C "HazLo" light. Again, non-metalic to prevent it from becoming one with a power system, bright enough for just about everything, waterproof, explosion proof, etc.
The Vulcan is great when there's a wide spread power outage and I need to really light things up.
My brother in law carries one of the Fenix lights and really likes it. Bought them for all his guys, but he supplies the batteries.
These new LED lights are pretty amazing, that's for sure.