I'm a huge fan of Tamrac Bags. I have three.
Biggest bag: Expedition 8x. Holds two camera bodies, f/2.8 300mm, 70-200, 17-40 and 24-105 along with 2 T.C's and there is still room left over.
My Expedition 6x holds: two bodies, 70-200, 17-40, 24-105, 2 T.C's and a 580 speedlight.
Both bags have a laptop pocket and plenty of additional pockets for filters, batteries, cards, wimberly sidekick, rain gear etc.... You can strap a tripod on as well.
I won't use anything other then Tamrac after loving mine for 2+ years.