I have several bags, but I know people have asked about the Pentax Sling Bag. I'm one of those that likes the Pentax label (and I can understand why others don't). Also, I've found this bag to be very versatile and more comfortable as a sling bag than my Naneu one.
The most surprising thing, though, is just how much you can get in this little bag.
Here are some pictures of the sling bag holding the K20D w/grip and DA*50-135 attached, plus the DA*200 and DA*300 in the top and bottom compartments. Of course, I still have room for the assorted cards, batteries and wired remote (I've got the wireless remote tucked into the grip). All in all, it carries an amazing amount, yet it's a pretty compact bag.
Here's the bag open to show the insides. BTW, I normally have the lenses in their individual cases in the bag, but took the cases off to show the lenses for the photo.
Here's the bag closed.