Exactly when and where I'm going out usually determines which light and where I carry it.
I have several small "tactical" lights. The two that see the most work currently are an E2e from Surefire and a Streamlight rechargeable, which is the same size as a Surefire 6P.
The Streamlight gets most of the use when I'm riding on the ambulance, or when I'm looking for a light to carry on my belt.
When I'm running on the truck, I also have a larger Streamlight Strion light, that I carry in my gear bag. Use it when I know I'm gonna be working in the dark (the scene of an MVA or something for example.)
But yeah, I'm more likely to have a flashlight on me then I am to have a firearm...only because I still spend time in NJ... the only tool I have more often then the flashlight is my knife :)