I cannot sing the praises of Tom Bihn enough. www.tombihn.com.

Fabulous bags, so very very well thought out. I have the brain bag and it holds my Macbook Pro, my QE2s, big bag of cables and flash drives and power supplies, my pashima, a book, DVD case, a pack of clothes incase regular luggage fails to make it, my medicines, etc. It's completely wonderful top to bottom.