I have the superhuman ability to see in the dark so I don't have a need for a flashlight, other than just to blind people so I went with a Surefire 6px pro.
I have a Fenix PD-30 that is awesome. It fits nicely in my pocket and is super bright in turbo-mode, with non-turbo-mode set up well for finding stuff in the dark without blinding everybody.
I think it's under a pile of crap in my apartment somewhere. I'm seriously considering cleaning to get it back. This is a testament to its quality.
I carry a Surefire G2X everyday its has a high and low stage it tends to be hard on batteries but works well in the corrections environment I work in. I carry it in a blackhawk flashlight case
I carry a Streamlight ProTac 1AA everyday and love it. It has high, strobe, and low settings and a great battery life. Plus it's a AA battery so its cheaper than a 123A...