To be honest, the light I use the most if probably this little LED keychain light that I bought at Dealextreme, mostly because it's on my key ring (hence always on me). They were 10 for $5 with free shipping, and I ended up getting a second batch in clear/white. While they're not as nice as the Photon, they are pretty decent. I accidentally ran one thru the washing machine and it still works! They're pretty bright for the size and have both momentary and permanent-on capability. They're cheap enough that I gave some away and used a few more as zipper pulls.

The flashlight I normally grab when I need a "real" light is my Pelican 2010 SabreLite Recoil LED Waterproof Flashlight. It's pretty bright, waterproof and the batteries last for 30+ hours. It's a good all around light, but a little bit big and heavy for the amount of lumens (it's a 2 x C cell light).

I suspect my most used light will now be my SUREFIRE E1B Backup LED Flashlight. I just got it today from BatteryJunction.com. While $139 is a lot for a flashlight (at least a lot for me!) I'm blown away by the power and the quality. And getting 24 free batteries (probably at least $35 bucks worth, or $80 worth if I had to buy 'em locally) takes some of the sting out of the purchase.