The best testament to how "good" something is would be its combination of function, durability and aesthetics (in that order).

Campagnolo Record/Nuovo Record etc. has been all three, throughout the ages. Unfortunately it's always been expensive, too. Same goes for boutique manufacturers (Paul Components, Chris King, early Ringle, American Classic, Cook Brothers, etc.).

From the late 60s to the early 80s there were very few manufacturers that could touch Maeda Industries for F/D/A. Their metallurgy was always outstanding. The Superbe Pro group they eventually came out with (too late, as it turned out) was better than anything before or since (IMO). Unfortunately, Maeda/SunTour decided to embrace complicated pivot design (vs. building on what they had that worked so well in the slant parallelogram), and Shimano came in and ate them alive with SIS.

Shimano was in SunTour's shadow for a hell of a long time (not many people remember it), but then determined to up the ante on its competitors, and as a result it came out with the 1-2 punch that settled it for everyone (e.g. Dura Ace 7400-series and Deore XT 7-speed SIS). I still use both groups, and they are still going strong on bikes in the current stable. Despite all the flack they used to take for Rapid Fire and for their brifters (justified), they still offered up bar-end shifters for retro-grouches like me.

Too bad they decided to make their parts proprietary and ass-fugly after about 1995. It's why Sugino is still with us, in fact.

SRAM took Sachs/Sedis/Huret technology, stole a little from Shimano and eventually became a player, but it doesn't really belong on vintage bikes.

And then there were the French. The good ones (TA Specialities; Mavic; Stronglight) are still with us. The ones that self-destructed or tried to kill us (AVA; Simplex; Maillard) are not.

Sleepers -
Takagi cranksets
Sugino cranksets and seatposts
Sachs/Sedis chains, cranks, hubs, freewheels
Miche hubs, derailleurs, etc.
Weinmann brakes (60s-late 70s)
Dia Compe / Grand Compe brakes, levers
SR/Sakae Ringyo anything from the late 70s through the mid 90s
Sun Rims
Matrix rims
Araya rims (double-wall; tubular)
Suzue hubs (particularly the sealed-bearing cartridge ones)
Sunshine hubs (particularly the track hubs)
Simplex alloy friction shifters
Simplex Super LJ derailleurs