Just to throw my hat in the ring, I have a Tactical Tailor "Removeable Operator Pack", and I love it. It's simple and straightforward. Big open main pocket, side open outer pocket, some molle real estate on 3 sides, and a spot for a bladder. (Holds a Source WLPS 3L bladder just fine.)
http://www.skdtac.com/Tactical-Tailo...-p/ttr.128.htm
Also a lighter "Fight Light" version:
http://www.skdtac.com/Tactical-Tailo...-p/ttr.139.htm
[Edit: Shit... missed the post where someone already mentioned this pack. So... nevermind. :-) ]