When I purchased my sons laptops for Christmas I knew they would need a good bag to carry them in. They go to their dad's house every weekend and the laptops go with them. Their laptops came in a bundle package that included this bag, it can also be purchased alone for $39.99.
This bag is a Hewlett Packard nylon case for laptops up to 15.4 in. The compartment for the laptop has 1/2 in. of padding around it. The bag is supposed to protect a laptop from a drop of up to 3 feet. We have not tested this out, fortunately. The boys do however, toss their bags around pretty good and so far the computers have been alright.
This is a very roomy bag. It has 2 main compartments. In one side there is the space for the laptop plus plenty of extra room for papers, software or whatever you need to carry. The other side contains 3 dividers that open up like an accordian file. There is a big zippered pocket on the back outside of the bag and three zippered pockets of various sizes on the front. It has a handy detachable shoulder strap, as well as a hand strap.
My sons use this bag to carry everything for their laptops, as well as their Nintendo DS Lites, games, papers and a change of clothes. It is made of nylon and is black so the dirt doesn't show and it can be cleaned with a damp cloth. This is an excellent bag especially for the price.