Okay, so I'm old
and this post will reflect that fact.
The best games I have played? The first one that really enthralled me was a text adventure called Colossal Cave Adventure, or just Advent. This was way back in the early 1980's. Zero graphics, just monochrome text on a green-screen monitor. Graphics weren't much too speak of in these days anyway, except in arcades with games like Galaxian. Text adventures were generally very well written and in my imagination I could really see the cave and the landscapes described. Fond memories.
https://en.wikipedia.org/wiki/Colossal_Cave_Adventure
In the 8-bit era: Without a doubt, Elite on my C64. The first sandbox game, the ability to build a career over a long period of play, 3D graphics, there was nothing that could touch it.
https://en.wikipedia.org/wiki/Elite_(video_game)
Along came 16-bit and I got an Atari STe. Two games come to mind: Armour-Geddon, a 3D game where you had to conquer a map using different planes, helicopters and tanks that you had to research and build first. Very immersive, that took me a long time to finish. Another great game from those days was Powermonger, a real-time strategy game, simple but very effective.
https://en.wikipedia.org/wiki/Armour-Geddon
https://en.wikipedia.org/wiki/Powermonger
The last game I really got into was Eve Online. I started playing that a few months after it was launched and it was an interesting experience to see one of the first MMO's grow. I was quite active for a few years but don't play actively anymore, it's too time-consuming if you want to achieve anything. I do still have my now 17 year old character and log in from time to time. Kudos to CCP for keeping a persistent game world active all that time, I still have stuff in my inventory from way back when.
https://en.wikipedia.org/wiki/Eve_Online
These days I really don't play games anymore, I am toying with the idea to get a nice setup for VR as that's another interesting development, but I'm not sure I want to spend 2000 or 3000 bucks for something that may bore me quickly. But who knows...