I'm a HUGE fan of Timbuk2 - I have several totes and a messenger bag (that I rarely use but that's another story
) They have some new designs that are more "professional" and less sporty (I'm still a fan of the brightly colored ballistic nylon, but I work in academia not finance so it's ok
)
http://www.timbuk2.com/function-ipad-kindle-laptop-bags