I have a Tamrac Adventure 9 to store all my gear together. Its is big and when fully loaded is heavy. Though I can fit my camera body along with 6 lenses or 5 lenses and my Gary Fong diffuser. I can also fit my SB-600 flash, lots of memory cards, 4 batteries, battery charger, laptop, cords for laptop, portable external hard drive, video camera, cords for video camera and a few flash batteries and some filters. This is what I use to store everything together (except for the laptop) at home and also use when we go on vacation.
I'm going to order another bag for small or day trips where I only need the body and an extra lens or maybe the flash. I'm leaning towards the LowePro Slighshot 200.