Talking camera bags, here, not something from CSI.
Sometimes I like to use a variety of primes and two bodies. I prefer to have lenses mounted on both bodies (hoods on the right way), and quick access to 2-3 other lenses. I have a think-tank belt system that mostly works (with hubba-hubba hiney and think-skin 50), but there are times when I prefer a more discreet shoulder bag.
The best I've been able to find so far is the Domke 5XC. I can fit two bodies with lenses on the top layer, and up to 3 lenses below, which are still easily accessible through their own zippered opening. On the top layer, even a mounted 75mm works (with 3rd-party shorter hood), if the other camera has something smaller on it (say, the 14, 17 or 20mm). However, there are a few things I quite dislike about the Domke.
First, it has that really long outside flap that closes with velcro. Well, it used to close with velcro 'cause I took it off. Now, there's just an extra-long flap that I generally tuck behind the bag whenever I'm actively shooting. Second, the pockets on the outside are a handy size, but they're not secured in any way. The other day I hopped a fence and fortunately heard two of my spare batteries hit the ground. They'd jumped out of the pockets, and it took me a while to find them in the tall grass.
Anyway, I live in hope that something better will come along, and there are always new designs appearing. I don't have ready access to a fully-stocked store, so on-line is usually where I need to begin a search. The Domke 5XC does the job for now, but any alternative suggestions are appreciated. BTW, usually I take two bodies, 14mm + DMW-GWC1, 20mm or 25mm, 45mm (either Oly or Panasonic), and 75mm, 2-4 extra batteries and extra cards, a CPL, ND8, brush and cloth.