There is a whole flashlight subculture, and the arguments are similar to Ford vs. Chevy, Glock vs. HK, etc. You can spend crazy money on them.
http://www.flashlight-forums.com/
http://www.candlepowerforums.com/vb/
I have an old school Maglite (the 4 D battery version) for around the house. The newer tech is pretty cool though - LED lights with multiple power settings, xenon bulbs with high power that will disable someone if you shine it in their eyes, etc. There are the cheap Chinese versions, the more expensive Chinese versions, and the really expensive versions (probably made in China too). Crazy...