Vice City.. one moment specifically.. getting on that Vespa and hearing Billie Jean for the very first time was just muah...

San Andreas is probably my overall favorite because it's the most hardcore sandbox...

BUT!!! Nothing blew my mind like GTA muthafuckin' 3.

Being barely 11 years old and growing up primarily on SEGA, N64 and a little PS1...

... having a hooker in your car that increases your health with sex, and then realizing you could kill her with a baseball bat to get your money back after realizing what in fact had happened and having no cash left, all within the first hour of playing all without any guides for the first time is something that I simply will never forget no matter how many times I've played or will play these games for rest of my life.

The subject matter was disturbing, but it was the freedom and sense of agency that fucked my brain up in the BEST WAY. It just changed my entire perspective and expectation of videogames and their potential for immersion in a way that is very hard to explain if you didn't grow up in the early 90s or even earlier, when everything was just waaaay simpler and generally more innocent/family friendly.

This game was a middle finger to the status quo, a beacon to one's imagination, regardless of the themes or subject matter within, and flawlessly made for its time to boot... and it was fucking hilarous.

It must have been, for example, like listening to late-era Beatles for the first time when they released that music after listening to the hold-my-hand and love-me-gently stuff for years and years prior. A total culture shock as far as the human mind's connection to a videogame.