I have a number of briefcases:
1. Some years ago, I needed a sturdy but stylish briefcase, and bought the Saddleback Classic briefcase (medium in chestnut); this is a stunning, indestructible leather bag, and has travelled with me to some strange places. The Saddleback is quite capacious, and will easily hold a computer, (my MBA - and its peripherals), note-books (for writing), iPod, (and peripherals), headphones, water bottle, pens, ink cartridges, business cards, and more.
2. Last year, (the Saddleback is quite heavy), I bought a relatively light briefcase (suede leather) from the Sandstorm company in Nairobi; a lovely briefcase for "light" work (MBA computer, notebook - for writing - and a few other bits and pieces).
3. A few years ago, on finishing up from a previous assignment, I bought a black leather briefcase from Church's - which was my main formal briefcase until this year.
4. This year, on my return from a year abroad, I treated myself to a stunning black leather briefcase - the Paternoster - from Adeney, Swaine and Brigg.
Both of these will hold computer, peripherals, iPod, and chargers, headphones, notebooks, water bottles, Olbas Oil and Tea Tree oil (I carry both everywhere), easily, and both look great and are well balanced which means you can carry them easily.