Check out the stuff that OKW offers, especially the EURO-CASE and VARIO-BOX stuff if you are about desktop test equipment stuff...
http://www.okw.co.uk/Also check out the partner stuff, ROLEC, TEKO and SERPAC.
Yes, these things are not cheap, but they are of really great quality, and you have several options of how to build the actual enclosure. For example, you can have stuff with a plain aluminium front-plate, but then the same enclosure with a transaprent lid, etc.
Plus, if you ask nicely, they will send you a sample of an enclosure you are interrested in.
Greetings,
Chris