As far as I am concerned, there are now only Two Flashlight companies.

Well, I will qualify that.

Among non-rechargeable, portable, handheld flashlights, I feel there are only two companies. Arc and SureFire. SureFire for when only the brightest clean beam light will do and runtime is not an issue, and Arc for everything else.

Arc and SureFire carried in combination make quite a team.

The fact is that 95% of the time, SureFire is overkill and costly to run.

Proper Portable on person Usage, 90-95% of the time, use to Arc-LS or Arc-AAA. 5-10% of the time, the SureFire is right for the job (use the right tool for the right job).

In the Arc-LS, if full brightness is not needed, save some batteries and use the Single AA holder.
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I had to limit this to on person portable. If I were to open up this to car or home light, the economy of D and C cell lights come into play a little. In the Home or Car, portablility is not as much of an issue as carrying on the body. If a C and D cell light existed with Arc quality. Then all you would need in the home or car would be Arc and SureFire. With this combo, the choice is Hard, long, and economical...Arc, or Fierce and short, SureFire.
.............................................Of course there is a place in this world for a rechargeable light which may open the field up a bit. Metal SureFire lights do not charge in the base so we might have to add Streamlight to the equation.

If D and C cell Arcs existed, the only Flashlight companies we would need for Home, Auto, and Person would be Arc, SureFire, and Streamlight.

...unless you need something with serious waterproof capability, for scuba diving or any situation which may involve extremely wet conditions.
For that, its hard to choose between Princeton Tec and Underwater Kinetics. They don't have quite the beatiful beam of the Surefires, but PT make some good, very bright, longer runtime lights that will easily cope with being submerged.
Don't get me wrong - I have an SF E2 and M4, and think they are great lights. But I don't know if I'd take either on a boating trip with me..

Graham

Ok, ya got me. I didn't think of water activities.

Well, as SF lights aren't really designed for underwater use, I would avoid using them that way. Even the Arc LS, with decent waterproofness, probably isn't a good idea.
My main reason is cost - SF lights are way too expensive to consider taking underwater.
I seem to remember reading somewhere 'never take anything diving that you don't want to risk losing'. I think this is pretty true. When diving you don't want to put yourself in a situation where you have to consider taking a risk just to save an expensive light. Often, if you drop something when diving, its gone..

Graham