i got a soft brief case when i worked at ace hardware back in 1999 and i have carried it ever since. It is hunter green and made by eastpack with the ace logo on it. It is probably 18" long but 6" wide by 12" high or so. It is soft so it expands as needed and has many pockets.
I usually carry....
FAR AIM for those innevitable stormed in arm chair pilot debates
All the charts for the area i plan on flying in
Timer
Kneeboard
yoke clip for approach plates
Headset
Approach plates for wherever i think i may land that day
a set of wet erase markers for the chart (it is in a plexi cover thing)
flight ruler
a few pencils, a few pens
logbook
headlight (flashlight for my head with red and white lens)
foggles
flight guide western states
e6b both manual and electronic
2 barf bags (you never know who is going to get sick)
2 glow sticks incase i ditch at night
solar blanket (looks like folded tinfoil)
an IR/non IR strobe in one. got it in the Marines for a Helo LZ..works good if you have to ditch
I think i carry a few misc blank flight plan sheets
dramamine in case someone feels they want to barf in my plane
I think that is it....it sounds like a TON of stuff but it really isnt that much once it goes in the bag...most of it is no thicker then a chart. The whole bag weighs 7 lbs and the bulkiest item is the headset which is not in there while i fly. The bag actually has nice neat pockets for most all of these items.