Hmmm, you have to define what you consider ethical.
Most people have probably heard of Bayer. They are a spin off of IG Farben. IG Farben used to have research facilities where they would test out chemical compounds on their Jewish prisoners during the early 1940s. They helped kill, very conservatively, hundreds of thousands of people.
Bad ethics on a corporate basis? They are my guideline. I could bring up many other examples throughout history, the point I'm making is that the worst company in the tech industry today is Mother Theresa in comparison. Really, the worst thing we can say about them equates to they don't play nice. Seriously, in the scheme of things Intel is Saintly
If you are looking for the people most responsible for the foundation we built 3D upon, that is SGi by miles. Pretty much anyone under mid 30s range could only read in history books about the early days of 3D. Shaded, lit and textured polygons? Yeah, seems obvious now- it wasn't. Not even close. On the hardware side of things SGi is responsible for the overwhelming majority of all the principles we use in real time 3D today. Iris GL which evolved into OpenGL is the grand daddy our game engines own their lineage to. That said, ~$10K was a good ball park to start with when looking at acquiring a SGi machine to actually do anything 3D with. To be fair, they were highly specialized machines with custom everything(CPUs, memory layout, entire system layout for that matter) nothing was comparable to regular PCs. SGi started it all and built our foundation, but they did it for engineers and movie studios.
3Dfx was the first company to push hard into the consumer space with a part based on SGi's principles, but with lower precission for gaming and the masses. 3Dfx came up with Glide that gave developers an easy to use API in a time when we were in sore need of one. DirectX was a joke at the time and OpenGL didn't run on consumer hardware(3Dfx had a 'miniGL' workaround for this that would work for gaming as several companies later did). 3Dfx largely copied what SGi did, but they made it so it was accessible for the masses. You didn't need to decide between a new car and the ability to play with 3D. Most of what they did was copying other people and then spinning it around with a shiny bottle of marketing and making it available to the masses.
nVidia at first bet on the wrong direction for 3D altogether. They decided to bet on quads instead of polygons, and their first part failed horribly because of it. After that debacle they had the Riva and refresh, the two TNT parts all of which were reasonably competitive with 3Dfx, then the GeForce. The GeForce is where nVidia started killing other companies off. They took a geometry transformation and lighting engine and bolted it on to a graphics rasterizer, creating the world's first GPU. At the time, in order to get this type of functionality you had to spend thousands of dollars on a E&S, Wildcat, SGi or the like hardware that had a separate dedicated geometry chip. At first this wasn't a huge issue, but the scales of economy eventually made it so the other companies couldn't hope to compete. nVidia took things that other companies had done, modified it, brought it to the masses and then killed a long list of competitors off in the process.
ATi is actually the oldest player I'm going to mention today in the graphics market, they dwarfed 3Dfx, nVidia and SGi combined for a long time making add in graphics boards for almost all of the major OEMs. They were a company making minimal level crap for a long time, roughly the Voodoo2/TNT era when they made their first legit attempt at a good 3D part(Rage128) followed a bit later by the Radeon. The Radeon was a critical bet for ATi, they could either follow nVidia's lead, or head in the direction of 3Dfx. Up until that point, the wise money was to follow 3Dfx as they had seemingly made the right choice at ever turn in their short history. Luckily, the people at ATi decided to follow nVidia and we were left with one big dog and the pup down the street in terms of market power. As ATi looked to better itself, they found a team of former SGi engineers that had worked together to make the graphics chip for the N64 called ArtX. This team seemed promising to ATi and they acquired them at which point they went to work on their first project for ATi, the Radeon9700Pro. As the years progressed ATi was then acquired by AMD who is using them both to bolster the high end of their image with their graphics parts and to give them advantage on their lower end CPUs by their superior offerings to Intel.
Intel's start in 3D came from Real3D, a former part of GE which Intel bought to build what amounted to a demo part for AGP- the i740. That was the closest Intel ever got to being competitive. They have mainly lived on passable parts that's strength was low cost since then. When the GPGPU threat was looming on the horizon they threw a few billion dollars at a radical(and ultimately failed) idea in Larrabee which was going to be a ray tracing part. Given what Intel was after, it made sense. Unfortunately for them, it seemed like they didn't pay close enough to the beginnings of 3D. They would have realized we didn't go that route in the first place for some very good reasons.
Which of those paths is the most ethical?
The elitist original?
The populist follow up?
The copy and kill one?
The survive, follow and acquire?
The inept clumsy oaf?
Which is the most ethical out of them to me is splitting hairs so fine it is absurd honestly. They are all corporations trying to part us from our money. In the end, clearly we think they are offering us something worthy of our money or we wouldn't buy their products. Each has followed a different technological and business path, none of them doing anything close to what I would consider truly unethical from a business perspective(talking about the GPU divisions here).