Yamaha. The attributes that come to mind are high quality and innovation. Yes, this is a company that truly puts their product through a rigorous testing proceedure obviously before it is released. On one side of the coin I hate to see products that have a lot of strange chips with no cross reference and that likely aren't even available any more for repair. On the other side, I rarely see failures! I fixed a DX7 up that looked like it got drug behind a truck! After a solder job on the board and cleaning contacts and so on...powered right up and has worked perfect every since!
And then they have their share of ground breaking product contributions. The CS50 was the first 'designed from scratch' polyphonic synth. (The Oberheim 4 voice was built from monophonic modules.) And the CS80 followed using the same voice boards and added the killer ribbon controller and many other features to become heralded as the finest of all analog synths by many. And then of course the incredible GX-1 of 1974, too massive and rare to have been included elsewhere on this page. And of course the GS and then DX series; the first highly successful fully digital synthesizers. Due to I guess... a lot of cultural/family pride or something it seems all their products from their fine Pianos to motorcycles follow this same pattern. This company isn't always the first on the block with a new idea, but they make sure they deliver products that are top quality.
The list of their products is extensive and go to the History of Synth Products link on Yamaha's page to get a chronology of synth products. It used to be ACCOMPANIED by the general technologies being employed at that time but they killed that link. ALSO Loscha has uploaded many scans including the Yamaha IC data and TX and YC service manuals.
SY-1/2 CS-50 CS-80 CS-60 CS-10 CS-30 CS-5 CS-15 CS-15D CS-20M CS-40M SK10 SK20 SK30 SK50D GS-1/2 CS-70M SK15 CS-01 DX7 DX9 DX1/5 TX816 DX21 DX27/100 DX11 SY77 SY22 SY55 SY99 SY35 SY85 AN1x CS2x VL1 MOTIF