The framerate. I had always played on console. Loved it. Went to a friends house and they were all like, "hey want to play some games?". So he sat me down at his computer and I had no idea what I was doing with a K&M. Once I saw the smoothness, I was in love. Then I started a new game, building my PC which got me even further addicted to PC gaming. My first gaming PC was an GTX 760/I5-4440. Since then, I've moved to a GTX 970 > 1070 > 1080 > and now a RTX 2080Super/9900K. Unfortunately, the "upgrade game" is a game I'll never beat...