I've never owned one of those fancy aviator-type bags they sell at the pilot shoppes. I have an Eddie Bauer "Guide" messenger bag that I got years ago for about $30 on sale. It holds my headset, AOM, a Jepp binder, flashlight, spare sunglasses, pens and a stack of forms and paperwork needed for each flight. And it all fits in a small cockpit. My recomendation would be to check the back-to-school sales in the retail outlets and office-supply houses and look for something similar at a good price.

All throughout college I used the same backpack I had in high school, and I even remain using that backpack for the most part if I need to lug around some lesson plans and a lunch or something, although I think my new current flight bag is one that my mom actually picked up at one of those flea market things for like 5 bucks, although now that I'm thinking about it, I'm not sure if it'll hold all the IFR charts (for when that comes up again) and stuff on top of all the regular stuff already in it. Like everyone else said though, any bag will do so long as it fits everything you need in it.

Goodly afternoon all...

When I first started to aviate back in the 50s my father bought me a World War Two Canadian Army back pack from a War Surplus Store which was awesome and could be carried with one hand also.
It carried everything I needed for university and flying.

Dad was still using his along with his RCAF Flight Bag, I did not want my grandfathers as it still had stuff in it from the Royal Flying Corps...

When I left the Royal Canadian Air Force I polished up my Flight Bag and gave it to our youngest son who still uses it.
Our oldest lad has my old army back pack and the last time I saw it she was still strapped to an old wooden prop I bought at a farm auction hanging on the wall of the hangar.

In the late 70s I purchased brand new a Round Top Flight Kit Bag, brown leather and it helped me fill several log books, carried my hand held computers, all aircraft log books and personal items.
Inside the top leather flap was inked in red the first name and birth date of each of our children so I never forgot a birthday phone call home or a present.

http://www.scottleather.com/

http://www.scottleather.com/product/detail.cfm/pid/2647

It sits here beside my desk still full of charts, memories, etc.

I can't quite remember what I paid for it but it is nowhere near what they are asking for them now as I just googled the site.
The Scott Leather Company in the United States is asking $319.00 American for them now.

I won't tell you what to buy but keep in mind that flight bag you get is going to be tossed into the back of a jeep, tossed onto a flight line bus, moved around on a cockpit floor, sat on, hold your hot tea or coffee and carry your brains and everything else you will need for a short flight during rain, snow, sleet, hail and sunshine.
That flight bag will hold every memory you logged into your pilots log book, things you will have forgot years later, but there, there in that flight bag will safely be kept your memories.

Good luck on your purchase...