I have this Swiss Gear backpack, apparently I bought it 7 years ago... They have many other styles, and some messengerbags.

I've abused mine. I've over loaded it both weight and volume wise. Compartment wise it has a padded laptop space, with space for a decent paper pad as well (plus a sub-pocket near at the top). The top pocket is ~6 inched deep, great for tossing frequently need stuff (plus a sub-pocket). Then a decent sized main pocket - I carried a pair or EqualLogic SAN controllers in here, or 2/3 shirts plus underwear, enough for a short business trip. Then the front packet, with subpockets, for charger, cables, keys etc. Side pockets for umbrella, plus two water bottle holders. Google images has some good results of the pockets if you search on GA-7305-14F00

Biggest down side; these are super common at tech conferances, so mine has a busted Lego luggage tag

I don't think this is the bag for you, but I do think the brand makes well though out and lasting stuff.