This is a super old thread, but interesting nonetheless.
My collection comprises a pretty good mix of mostly "industrial" brands, all in complete sets. I absolutely LOVE socket sets that come in metal boxes, with accessories. It seems very old-school, like a tradition that began during the dawn of the industrial/automotive tool age. I know these days it's all about the undeniable value of the huge sets from Sears, or the "modular" approach to tool collection building with socket sets on clip rails or Hansen trays. But if you ask me, the metal-box sets from Blackhawk and Williams and SnapOn and everyone else from the '20s and '30s are just so neat! The post WWII-era Blackhawk Nuggets 7/16"-drive set in the torpedo case may just represent the pinnacle of socket set design and content, and is also a great reminder of what were Blackhawk's glory days.
In my shop the representation is as follows, from the greatest percentage to least:
Proto (By far the vast majority)
S-K (Older tools from when I was just starting out - I'm very fond of these!)
Wright
Blackhawk (The USA-made ones represent a good value; great industrial tools, just packaged and priced in a way that's friendlier for non-tool-oriented folks)
Armstrong
Challenger
Williams
Easco
Fleet
Husky (1/2"-drive USA-made SAE set in metal box, from Home Depot circa 1997. Nice.)
Allen
K-D
Cougar (Wright's Blackhawk-equivalent, made by Danaher)
Craftsman (one set is a neat 1/4"-drive all-deep SAE set, in a tiny little blow molded case with an RHFT ratchet and an extension).
Facom
Koken
Wilde
Beta
There are, of course, a few individual pieces too, including a Snap-On Ferret 7/8" deep socket that I bought at a flea market to remove spark plugs from old flat-head industrial and agricultural engines.