I've often been frustrated by searching for enclosures. Most enclosures are quite deep, but not very high. I often need the height/width for front panel space (eg. LCD + buttons), but don't need much depth, for example like many recent instruments (eg. Rigol DSO). Larger cases (like most bench equipment from manufacturers like Agilent) are also hard to find.
Many seem really ugly and scream 'amateur' or seem designed for mounting to the wall in industrial settings, although there are some exceptions like some from Hammond.
Even with the parametric search from Digikey, you can't just ask for a case with inside dimensions at least l x b x h, you have to scroll through the whole list manually.