I recommend Swiss. I got it for free when my dad bought his POS dell laptop. When I started college I found it in my closet and figured I'd give it a try. Haven't used anything else for two years. It holds my 15.4in WS laptop, but anything bigger I doubt. It fits pretty much perfectly with no room...which I like so nothing is moving around. I currently have two text books in there (about 4-5 inches total) along with two 5 subj notebooks, graphing and sci calc, a few cds, external harddrive, power supply for said laptop, and a few folders. I'm sure I can squeeze more in, but even when there isn't much in there, it stays flat and doesn't look bulky. Plus the cushions and some fancy airflow pad things make it comfortable, even when it's heavy.
Sorry about my grammar...I got lazy half way though the post lol.