One light: PT 20 because....
It uses cheap, available AA's. Cold weather or long runtime? Use Lithiums. Do you want rechargeables? Use NiMh or nicad. Or you can use alkalines.
It uses cheap, available PR based bulbs. You can underdrive or overdrive them. You can also use PR based 5mm LED lamps, the PT Matrix module, or even a luxeon (Everled). The LED options offer different lamp colors.
It's waterproof.
It's arguably pocketable.
It has a lanyard.
It comes in different case colors.
Depending on what sort of beam you want, you can use faceted or smooth reflectors.
If you want a really bright light you can use 4x1/2AA's and a higher voltage lamp.
It can be reconfigured with different reflectors, lamps and batteries in a matter of seconds without tools.
They're cheap. As little as 8 bucks or so on sale.
PT has, usually, great customer service.
Two lights? Another PT 20 or a PT 20 and a PT 40. The parts are interchangeable.
No, it isn't the perfect light but it is a great compromise among many factors. Don't pooh-pooh it because it's cheap. Yes, I have Surefires too but this is one great light for the money.