When the PS1 games were relevant, I can't remember if I had never heard of GTA or just saw the top-down view and was turned off enough by it to not care to try it out, but I didn't get into the series until 3, when that game was all the rage. 3 completely blew my mind, by how much you could do in that world. The main PS2 trilogy I played several times over; I 100%'d all of them, including the Stories games when they were finally ported over from the PSP. I was also a massive Driver fan from the original PS1 game, so I really enjoyed the back-and-forth jabs the two series took at each other. Somewhere in there I picked up a PS1 trilogy set to try out. I got a little ways into the first game but couldn't get into it; I'll have to revisit that some time.
4 and 5 were good, I of course 100%'d those as well, but the PS2 games are still the best, especially San Andreas. I got into San Andreas like nothing else I've ever played. Taking that 'secret route' into San Fierro that keeps the cops off you while that part of the map is still locked, doing as many odd jobs as is possible to work up that completion percentage before getting into the story, hacking the game with a Code Breaker, watching the movies people on YouTube were making from the game... San Andreas was incredible.
I played 5 online a little bit on the PS3, but I'm not an online gamer and from what I've seen of GTA Online it really disgusts me. I hope the next game, if it ever comes out, doesn't suffer the same fate of not only milking the online aspect while completely ignoring us offline gamers, but the saturation of fantasy action. It's sad watching the same thing happen to Red Dead 2, which might have been a San Andreas-like experience for me, with how much I love that game offline. I only bought RDR2 to play on a friend's PS4, though, so I haven't gotten too far into it outside of the story and most of the 100% checklist; I'm skipping the PS4 for myself and waiting for a good time to buy the PS5 and make use of its backwards compatibility. Here's to hoping we get a new GTA this generation.