1972 Atari - Pong
The Atari Pong is a classic. Everyone who played a game has heard of Pong.
It was the original PvP competitive game that in my mind paved the way for eSports and gaming rivalry. Even though we now see Pong as such a basic game, for it's time, it was ground-breaking.
1995 SONY Playstation
The SONY Playstation was the first console I ever owned so it has always been close to my heart and the thing that initiated my love for gaming. I used to sit there for hours and play until my hands cramped up.
There were never that many games that were of a high quality for it's time but the ones that were were absolutely incredible.
1994 Blizzard's Warcraft: Orcs and Humans
Blizzard's Warcraft was the first Real Time Strategy game that I ever played. It featured a fantastically immersive story-line and a deep lore that I seemed to connect with. Even though this game came out 1 year before I was even born I still enjoy playing it to this day.
It paved the way for games such as Starcraft and Defenders of The Ancients (DoTA) which are exceptionally competitive and a lot of fun.
Away from the competitive side of gaming it also contributed to the best RPG ever made, World of Warcraft. Where the lore expanded and the story line dove deeper. For me, this was total heaven.