Well, that question is more complicated than it might at first seem. A lot depends on the time period you are talking about. From the early days to the late 70's things were relatively consistant. At the bottom there was generic, heavy, I believe low carbon steel that was typically welded into a 40+ lbs bike sold through department stores and auto parts stores and the like. Then there was "house brand" tubing produced by many of the major bicycle manufacturers in house that was lighter, thiner, hi-carbon steel, also refered to as hi-tensile steel and typically brass brazed with lugs. Those bikes were typically in the 30-lbs range with lots of steel components but could build a nice sub 25-lbs bike with aluminum components. Until the 60's or so there were some Italian brands that were considered, at least by the cognoscienti, to be second tier like Tullio and Falck. Then you get into Reynolds and Columbus. Reynolds made a straight gauge 531 tube set which I guess would be the start of the high-end tube sets. Then both Reynolds and Columbus made, I think, three weights of tubing. For Columbus I think it was KP, SL, SP. For Reynolds I'm not sure what the names were. These were all of equivalent quality. The builder would simply use the tubing appropriate for the frame he was building (i.e. - small vs large frame, racing vs touring, or special purpose bikes like time trials and record attempts). In the late 70's things get considerably more complicated. Columbus produced a complete line of tubing. Most commonly seen were Aelle, Gara, Aelle-R, Cromor, SL, SLX, and later TSX. I don't know the Reynolds lineup as well but I'm pretty sure they kept the straight gauge 531, DB 531, and added 753. By the 90's there were all sorts of attempts to make steel competative with the new aluminum frames and shaped tubing became all the rage. I won't even pretend to be able to name those. And of course the Japanese brought out complete lines of tubing as extensive and as good a quality as Columbus.

Well, that's my best guess. I'm sure the real experts will be along shortly to correct me and expand on what I said here and post some links to catalogs.

Oh, BTW - I would say that any of these tube sets except for the heavy gas pipe crap used on the department store bikes. Even the relatively thin walled oem hi-tensile tubing manufactured by the bike companies is not bad stuff.