What Was the Most “Game-Changing” PC Hardware Release Ever?

Looking back at the history of PC hardware, which single release do you think changed the industry the most?
It could be a CPU, GPU, storage solution, or even a peripheral that shifted how we use PCs. Examples might include the first SSDs becoming affordable, the release of Ryzen shaking up Intel’s dominance, or the introduction of G-Sync/Freesync for smoother gaming.
Curious to hear what moments the community considers true milestones.