Some nice oneshttp://www.crumpler.com/us/Camera-Bags.html?LanguageCode=EN
any favorites?
All the ones I have are Lowepros.
As with the cameras they hold though, it's always best to get your hands on them and see how they feel. http://www.vistek.ca/results/BagsCases/bags%20cases-camera%20bag/Lowepro/Camera-Bags-and-Cases.aspx
I love the domke bags. My little 5xb is perfect for a 1-2 cameras, one extra lens and some goodies.

If you have a lot of kit. The bigger bags from ThinkTank, LowePro, and Tenba are all good. Pelican hardcases and Lightware cases are also bueno.
But really, for anything small. I tend to roll with Domke. Their padded adjustable inserts are the best.
Crumpler is nice. I would say that to the non photographer, the crumpler blends right in as a messenger or backpack. It doesn't necessarily scream "expensive camera gear!" to the common man so it might stand less chance of getting nicked if you happen to set it down in public. If your thief is a photographer your screwed because they know the quality/cost.
I love the Domke as well. I lug my shit around in an F2. It's not too huge and it's versatile. Super high quality. I've had mine for years and have abused it really, and it pretty much looks like new. A little dusty on the outside but right as rain on the in. RD's 5xb looks a little more compact and portable.
http://www.bhphotovideo.com/c/product/15974-REG/Domke_700_02B_F_2_Original_Shoulder_Bag.html
the F2 bag is classic. I still have one I use for my dSLR studio kit (swapped out with a Lowepro studio bag, depending on how many lenses I need). Could get an F1, I suppose, but I already have a dozen camera bags.
I love that they make a waxed/oil cloth version for better weather resistance.
Their gripper strap is the best.
Originally posted by: rogue_designer
Their gripper strap is the best.
My favorite part.
It's soft as well making it really comfortable to use.