Good advice from Unicorn.
Basically, if you will use the light daily (or nearly so), a rechargeable light makes sense. But not for your vehicle.
If you just want something that will be there when you need it, a G2 with extra batteries cannot be beat. The light itself is an inexpensive, yet quality, instrument, and the long "shelf life" of the 123 lithium batteries means you can throw the light in the glove box and forget about it; until you need it.
Something like the Streamlight 3AA Luxeon Task Light is ideal for around the house. The controlled environment indoors helps preserve alkalines, and you can employ rechargeable NiMHs if the light gets used a lot. This light is small and handy enough to stick in your back pocket while doing hosehold repair chores, etc.; powerful enough to use outside if needed; and durable enough to survive being dropped, banged around, etc.
Be very careful; you're on dangerous ground here. Once you "get into" flashlights, you're lost. I've been using them professionally for a very long time, and always looked at them as just another tool. Since finding this forum a few years back, I've spent untold amounts of money on "Oooohh, that looks cool; let's try one!" stuff.
Its more than an addiction; its a sickness. And a very insiduous one; you're hooked before you know it. /ubbthreads/images/graemlins/icon3.gif