DCS World is the biggest reason that my most recent build had 64Gb of RAM.

Hot Dogs, Horseshoes & Hand Grenades (H3VR) sold me on Vive (then later Index) as well as an upgraded second PC just for VR gaming. I've certainly enjoyed other VR titles but H3VR is by far my favorite and alone was worth the "investment."

A few games have gotten me to do that over the years.

Mass Effect: Legendary Edition was what finally convinced me to fit a 1TB SSD, and Control was what convinced me it was finally time to get a ray-tracing card.

My brother brought me Tiny Tina for us to play online together and my video card couldn't play it so I had to upgrade...

New World. Friend at work recommended it, so I bought it. Couldn't get it to run. This was during the GPU shortage a few years ago. Spent weeks on a wait list and finally got something close to 2x MSRP bundled with a motherboard. At that point I figured I should just go all in and do a full upgrade. Finally got things running and lost interest in the game 2 hours later - haven't touched it since. Now I mostly just play RimWorld.

Weirdly, Fallout 76. Some friends bought it for me for my birthday so we could all play together and I was struggling, so I updated my system and honestly had a lot of fun, as janky as the game was around launch. Lots of good times with my friends.

Hell Let Loose. Not because its terribly hard to run, but my OC'd 590 happened to die while I was playing it.

Cyberpunk 2077 at launch....at least I got myself an awesome computer!

During covid I got bored and upgraded my system, not for any particular game but justified it by mining crypto when I wasnt using my PC

I wanted the most extreme sff pc I could afford at that time. I really didn't need an upgrade, but I was at the end of the am4 platform with my 5800x3d, so am5 with all it's quirks was it.

Three main phases.

1. A long time ago was EverQuest. Some online friends figured out you could take the beta exe file testers got and distribute it to others, who could run and get the updates. So I tried it out and got to see the world of Norrath. At one frame every five seconds. Turns out the integrated graphics wasn't going to cut it, so I got my first ever graphics card, a lovely Riva TNT. Wow, the difference.

2. It was time for a new PC anyway, so along with getting the best I could afford, I had to have a new game to test it with, right? That was back when you could get a free Halo CE along with a Windows purchase, and I had been following the Halo development videos so it was a natural choice. My computer's first sounds were the opening menu soundtrack.

3. Current PC, again it was time for a new one since the last was #2, and if you know the dates for Halo that was "ancient", although it had done well for most things I had thrown at it. The game that I already had been playing but wanted an extra boost was Elite Dangerous. Not only did I get an upgrade in graphic card, CPU, memory, etc., but I obtained several used 24 inch monitors in order to have three screens, something I couldn't manage with the previous PC/card.

For me it was PUBG. I had been away from pc gaming for a while, and my friends wanted me to join them in PUBG. I had an old laptop with dedicated graphics, but the game was so horribly optimized that it was unplayable. I built my current rig then.

Starfield is my current 'need' to build a new PC - What i have, i built in 2017 because my PC at the time was a cobbled-together mess and i wanted to treat myself, so i built all-new with a 7700k, 32GB, and a fresh 1080ti - It's been great all this time, but really is showing its age. So next up i'll be building something to last me at least 4 years and it may well be: 7900xtx (but waiting until towards the end of the year in case something better comes out, or waiting a little longer is justified), 7800X3D, 64GB DDR5, PCIE5 mobo and a 2TB M.2, a 2TB SSD and a 1200w PSU.

If that doesn't last me 4 years.....

And i at least know i can slam any game to max at 4k 120hz (bar RT) without worry, and perhaps with FSR.

Ideally i'd like to wait for a card after the 7900XTX, maybe this supposed RDNA 3.5, or maybe the 8000 series if it's soon enough. All rumours right now, so i will at least wait until maybe November or early December and then cash in on the included Starfield with the CPU. Bonus!

Originally built my PC because I heard reputable rumours of Destiny 2 releasing on PC. Already had an ok laptop that was showing it's age, but built a PC with an i3-4170, 8GB of RAM, and a GTX 1060 3GB. A year after that I upgraded to a Ryzen 5 1600 because dual core in 2017 lul.

iRacing has driven (heh) the vast majority of my PC upgrades over the past few years. Changing from monitors to an Oculus had me upgrading GPUs back in 2017, I got a 3080 two years ago which let me upgrade to a Reverb G2, then realized I was getting CPU-bound fps drops so I ended up with a 5800X, all in the interest of higher settings and more cars on track at once. Unless someone comes out with a worthy upgrade to the Reverb, I think I'm set for a bit.

Nier Automata made me do my first upgrade since I got my PC back around 2010. I was very excited to play it, loaded it, and slugged below 10 fps in the opening scene of the game. I was incredibly sad, but undeterred in playing what became one of my favorite games of all time. Got a 1070, came home, and forgot about power usage. So I had to go out again and get a new power supply. Then it became smooth sailing. Nowadays I'm looking to upgrade my whole PC since my I7 is probably slower than today's i3 maybe ( I know it's worse than an i5 now) but no game has given me issue right now (except D4 making my computer into an airplane.)

MMOs were a big driver for me back then. GW2, WoW made me upgrade my GPU a few times.

Company of Heroes made me upgrade my RAM from 6GB to 12GB.

Most recently, Elite: Dangerous with the Odyssey expansion persuaded me to upgrade from my GTX 1070 to a RX 6700 XT.

Jedi Survivor, it was a buggy release.

Do not buy parts for Starfield until it releases and reviewers report in.

I most recently upgraded due to no mans sky constantly struggling. But upgraded enough to get cyberpunk and path tracing. With it being out for iver 2 years when i upgraded, those hardware targets were known.
This machine should cover me for starfield though.

Starfield is unknown.

PUBG

My next computer is being built for Cities: Skylines 2 for sure.

PC builder simulator.

(actually the witcher 3)

Treated myself to an ultrawide and rtx 3070 during the pandemic for Cyberpunk and Battlefield 2042... and for work and study, of course. Cyberpunk was a bit choppy, but I got used to it--thankfully only ever crashed a few times during my playthrough. Played Horizon: Zero Dawn, Apex Legends, Star Wars: Fallen Order, Titanfall 2, and some other games, mostly FPS/shooters (NMS, hunting games)... then it became a glorified Fall Guys machine for a bit until I got a PS5... next upgrade may be when the 4090s come down in price, or whenever 24 GB of video ram is more affordable (I actually could use the extra ram for work-related experiments). Maybe a sidegrade to the steam deck?

Rdr2. Was using a i5-3570 + 8GB DDR3 1333Mhz. Jumped to a Ryzen 5 5600+16GB DDR4 3600. My RX570 still holding.

No single game has gotten me to upgrade my PC, however if RDR2 released on PC at the same time as consoles, I would have upgraded for it. I ended up buying a PS4 to play at launch, and bought it again once it came to Steam (didn't need to upgrade to run it by that point).