Ok, "bag" is a bit of a misnomer because I often travel with quite a few bags. The one that I will be walking through today is the "dSLR bag". For those of you who don't care to read though to the end we will start with a list.
First of all, everything here fits nicely into a Lowepro Pro Trekker AW (mark I). I have been sorting through a lot of stuff lately and I am sure I will have to update this list shortly as I trade a few more things around.
Nikon 80-200mm af-s f/2.8 IF ED
Nikon Micro Nikkor 60mm f/2.8 af-d with custom hood (more on that later)
Nikon 50mm f/1.8 af-d
Nikon 28mm f/2.8 af-d
Nikon 19-35 f/2.8 af-s IF ED
(2) Sandisk Extreme III CF cards (4gb)
(2) Sandisk Extreme Pro CF cards (8gb)
(3) Nikon SB-28 speedlites
(2) Yongnuo YN-460 Speedlites (ported)
(3) Phottix Atlas transceivers
(2) YN-602 transmitters
(5) YN-602 receivers
Charger for D200
15min Charger for AA's
(48) Sanyo Eneloop low discharge AA's
(4) speedlite grids
(4) color correction gel sets
(2) Pixel hotshoe to PC adapters.
Misc. cables for triggers
Misc. backup sync cables
So there is a lot of stuff in there. This is the kit that I basically always travel with. There is enough of a variety of gear in there that I can show up on assignment with little or no idea of what to expect and survive. This is also how I store my most frequently used gear. The idea is that I could get a call about something and be in my car with everything I need in less than 5 minutes.
This bag is almost always accompanied by a small lighting kit consisting of:
(2) 9' light stands (occasionally more)
(2) Super clamps
(4) umbrella swivels
(4) "A" clamps
Suction cup mount
various umbrellas 25", 32", 45", 60"
I shoot 95% of my portraits on location with these two bags and a laptop case. If I am shooting available light I skip the lighting kit.