My 2 cents, for what its worth:
I am a huge GTA fanboy, at least pre-GTA IV, but that is another whole conversation. The fact that this game is a decade old, with decade-old technology, graphics, and resources is a testament to its greatness in that it is still remarkably playable. I still can't get enough of III, VC, and SA. In fact, the main reason I am now such a huge Saint's Row fan is because the first three games play like San Andreas sequels on the next gen of consoles. I still have the ability to get completely lost in the huge map of San Andreas.
People hating on the story and career missions should take a moment to realize that a game like this, to be truly enjoyed, has to be graded on a huge technological curve to a large extent. To me, all the great PS3/360 games that I love best now, all seem like they embody at least some of the great parts of San Andreas: Just Cause 2, SR, SR2, SR3, SRIV, even Burnout Paradise, all borrow some of their ideas, hell, many of their ideas, from San Andreas.
Honestly? In my opinion. nothing Rockstar has done with GTA since SA, LCS, and VCS, can hold the smallest candle to San Andreas. I know some people consider the missions boring and linear in SA, but you know what? Its only because the PS2 was so limiting and the game was so incredibly huge, demanding seemingly more than the console could ever give to it. To me, though, San Andreas is analogous to those great Bogart and Marylin Monroe movies. Sure they can't compete in technology or special effects to today's movies, but WOW if you can get past the old fashioned cinematography of those films made long before our time, man can you come away with an unfathomably delicious experience.
San Andreas may be the videogame equivalent of black and white movies, given how fast technology evolves, but there is more sheer joy in this game, even now, than probably 99% of the games out there that are "technically superior" in every way. I know GTA IV and V are blockbusters and the fanbase loves them. But I have ALWAYS lamented the fact that regardless of V being set in "Los Santos," it has never, ever felt like a true sequel to San Andreas to me. For GTA, at least for me, San Andreas sits atop the pinnacle of what makes a sandbox game truly and remarkably great. Yes, sometimes for the first few minutes of play, before my eyes adjust, the game can be a bit of an eyesore. But after that, once I begin to once again get completely lost in it, I start to realize that the old saying is wrong. Because you really can come home.