If "bomb proof" is not a necessity, just decent quality, some I know of:
REI Lookout (own it):
http://www.rei.com/product/747524. ~2400 cu in. Nice fit for me
Kelty Redwing 2650 (almost bought the 3100):
http://www.rei.com/product/734324. The medium should be the 2650, the large should be 3100. Look around, I usually see this for as low as $70.
Kelty MAP (want it):
http://www.amronintl.com/tactical/products.cfm?id=631. This site always has the best non-ebay prices I see. Disregard the 3500 cu in in the description. It is 1950 cu in. Knew a couple of SEALs that have this. Like it for a carry around bag, good size for what you are looking for.
REI Traverse (used to own it):
http://www.rei.com/product/747525. I am a Scout leader and have three small kids. I needed more room so moved up to the Lookout. Decent pack, it could pinch a bit around the neck if I weighed it down much.
Lots more out there by North Face, Jansport, Piper Gear, Camelbak, etc. You really need to think about what you want to use it for, how you want it to look (tacti-Cool, commercial, etc) and just start trying them on. I love REI to do that, but you can find better prices at times on line, or at spots like Sportsmans Warehouse.
Hope this helped.