The hardest thing after choosing a camera or lens is what to keep all those things in. Bags come in all sorts of shape,sizes and colors. There are so many options to choose from, it can be overwhelming. Is there a perfect bag out there? If there is, I haven't come across it yet. There are some people like myself that have multiple camera bags. Each bag is for different gear loadouts. Trying to find just one prefect bag is hard. But then I recently came across the Lowepro Transit 350AW. It look like this could be a good fit for most occasions.
It's what I would call a "pro" commuter backpack. It can hold a 15" laptop or a tablet and has a small space to carry non-photography related things. The reason I call it a "pro", is because it can fit a gripped body and a 70-200mm F2.8 lens attached. There is still plenty of space to spare for additional gear.The inside is adjustable and you can change the layout to suit your needs. You can pull the camera from out the top of the bag or have it set up for you to pull it out from the side.
The bag features a squared off bottom, even when loaded down with gear it can stand up on it's own. My other favorite feature is the built in rain cover that comes in the all AW series. I can't have a bag that doesn't have a rain cover. I've been caught in too many summer rainstorms in Florida not to have a cover. My only gripe with this bag is the lack of side pocket for something like a water bottle. But then again, where would it go? One side has the camera quick access and the other is side is for your tripod/monopod. My solution to this was buying the bottle pouch. It attaches with velcro to the loops on the side that can hold the tripod. Other than that, there really isn't anything to complain about. It really seems like a bag that can hold your gear and some other daytime essentials for people on the go.