There are two, I can't decide.Greetings!
Technology is changing so quickly that it can be tough to develop a deep attachment to any one item. However, through the years we've all likely made that one really big purchase that left us feeling like we were way ahead of the curve.
When I first caught the bug to build computers from scratch, the litmus test for any GPU was how it could run Crysis. At the time, next to nothing could really do it justice.
Many years after it came out, I was still using that game to test the power of graphics hardware and the GeForce 7800 GTX was my first card to run everything on high settings. It wasn't a perfect experience, given limitations I had in other hardware, but that is the first time a graphics card really blew me away.
What graphics card/GPU do you have fond memories of using?
My first proper GPU that I used for years and loved is the MSI GTX 460 1GB. I loved that card and I still have it, still can play some games. Recently put it in an older computer with an i5-2500 and 8gb ram, could still play some games. Took me back.
Then there's the GPU that I absolutely loved for getting even better once DX12 games started to appear: the XFX R9-280X 3GB. That's still a nice alternative to a GTX 1050ti to this day. Amazing value.
And then the runner-up: the AMD RX 580 as a used card, especially the Sapphire Nitro+ and Pulse versions. Such an amazing value especially for the 4GB version (which is totally fine for 1080p), you can pretty much max out most games or at least run them with very high settings and 60fps for such a low price.