Lowepro GearUp Creator Box XL II

The flexible dividers make it so easy to reconfigure for a full-frame body and a couple of lenses, and the padding feels substantial enough for real protection. I've been using it as a standalone day pack insert, and it's perfect for keeping everything organized without the bulk.

Finally, a bag insert that actually fits my full-frame body with a 70-200mm attached vertically. The adjustable dividers are thick enough to keep everything from shifting around in my daypack.

I was pleasantly surprised by how well the foam padding absorbs bumps during daily commutes, and the zipper opens smoothly even when the box is packed full. It's a solid, no-nonsense organizer that fits my DSLR and a few extra lenses perfectly.