Definitely AMD, they give people enough data to build open source drivers and you will simply have better support and integration with those. It's not like Nvidia drivers are awful or anything but they just cause annoyances and especially with new technologies like Wayland (Display server protocol that most of Linux is about to adopt) they can be a pain. AMD GPUs work great on Linux, have far better pricing rn and they have no issues with Windows ether, even if you used Windows more I would recommend AMD rn for the pricing alone!

I just swapped from NVidia to AMD, since Proton was not working under NVidia for Starfield at launch (and I’ve generally been unhappy using NVidia for a while).

I can finally also use things like Wayland where NVidia just doesn’t support it well enough to be a good option (e.g., weird issues with full disk encryption unlock screen, no night light support)

I know CUDA and productivity apps might push you in the other direction, but if your main priority is gaming, I suspect AMD will be nicer. My first impressions is that it plays way better with Linux and reduces headaches that shouldn’t exist but you’ll deal with under Nvidia.

I'm using Intel Xe embedded graphics and they are suprisingly good. This is probably the first embedded intel chip that can run games. It's basically on par with low-end Nvidia and AMD cards.

I have used an GTX 3070 with no issues for the past 3.5 years, before that I used an AMD Vega 64 with no issues. I think if I were buying a new card and could stomach the prices I'd lean towards a Radeon 7900 XTX.

I have a 2070 super that I use for gaming and tensor stuff. So far no problems with Arch, X11, and i3. I don't really have brand loyalty though, when I last bought a graphics card I just considered what was going to be best for my price point.

I have an NVIDIA 1060 and it is such a pain in the ass to deal with. The number of random problems I've had with it has put me off from ever buying a computer with NVIDIA hardware ever again. Save yourself the constant walking on eggshells and get AMD.

I’ll sometimee switch to Windows to play specific games as well.

That is probably the best answer. Linux is a serious POSIX compliant UNIX like operating system. Gaming on Linux is pretty much an afterthought, with game studios not producing native Linux ports. Last I saw was Starsiege Tribes II, which while they made a native port, they let it languish and die. Most of the games out there will require Proton (A version of Wine) or similar. While that trick can get many games to play on Linux, usually it is not supported by the game studio that made the game, which is less than fun when games games end up having issues. Worse, games running ainti-cheat can mistake that fake windows environment as a hacked system designed to try and cheat the game, which can get you irreversibly banned from such a game. Not worth the risk. Finally, when issues with this compatibility wedge come up, and they will sooner or later, often gamers, such as yourself, take to blaming Linux, instead of the gaming studios or the compatibility wedge, making Linux look bad to others and hinders Linux desktop adoption rates. Do everyone yourself and Linux a favor and just run the games where they were made to be played, Windows... unless it's a native Linux port or even better, was written for Linux from the start.