My favorite compartmented organizer is the Stanley 25-Removable Compartment Professional Organizer. The lid is clear but doesn’t seem brittle, and the compartments are removable (nice if you want to grab one or two instead of the whole thing). Matching this, but deeper and with larger compartments, is the Stanley 10-Compartment Deep Professional Organizer, great for larger bolts and nuts.
Harbor Freight has a similar line – which I was about to say, isn’t that much cheaper, but turns out, on sale it’s about half as much. HF’s version is a little deeper, meaning the two are not interchangeable – you can stick a Stanley compartment in the HF, but not vice versa. I use a flat file cabinet for tool storage (totally affordable at local used office furniture resellers, keep your eyes peeled) and the difference in height means Stanley just barely fits without scraping, where the HF causes the drawer to bind a bit.
Both systems stack well on one another. The other thing I like about the HF is that they have a half-sized model that still stacks well (one full sized organizer will stack fine on two half-sized placed next to each other).
The trade-off with removable compartments is some flexibility. For longer bolts or drill bits, I remove two or more compartments in a row and set them in the negative space created. The other plastic bins (held in place by ridges on the lid) keep this space in one place.
Both types have handles that allow you to carry them, and the hinges, while plastic, have proven robust in use.
[Note: This is an alternative to the harder to find and more expensive Sortimo. --OH]