It's difficult for me to single out what makes the game special to me - rather, it would be easier to single out the things that don't, because they are by far the smaller number in this context.
Simply put - pretty much everything about the game is special to me.
The intro of FFVII pretty much highlights everything I like in visual aesthetics, musical composition, cinematography, and genre.
2 minutes into the game, and I knew I loved it.
The "modern-punk", 90's anime, vibrant yet dirty urban settings with high-fantasy elements, and a Star Wars-esque/traditional hero's journey narrative, complete with a more paced strategical game-play as opposed to the action and platform games I usually played, just blew me away.
Here you could have a character that looked like a Super-saiyan wielding a giant sword and blasting magic around in a world with cars, steel-pipes and retro technology that was recognizable and dear to me at that moment in time - all set in world and a setting that was in many ways analogues to my own at the time.
It captured the spirit of the times, while creating something entirely unique for its medium in terms of the world and setting (despite recycling a lot of narrative tropes and game-play mechanics, which were already near and dear to a lot of people).
Add to the mix that it was the primary factor in fueling my desire to become proficient in the English language, and later learning Japanese and then moving to Japan, you might say that the FFVII is a cornerstone in the hows and whys of where I am today.
It was also a binding point for me socially speaking - stimulating countless of hours of conversations with people I would never have known if it weren't for our common interest in this game, broadening my horizons in a way no other piece of art has.
FFVII, back when I was a kid, was one of the few things that could enable a pale white kid from the suburbs to sit across a table with downtown aspiring thugs and laugh in glee at the same thing.
Working class kids, jocks, geeks, goths, the guy who held up other kids for lunch-money, or beat them to a pulp in the bathroom stall - they could all spare 5 (0r 30) minutes to talk FFVII and forget their dumb little cliques for a moment.
That was something truly unique and precious in that era of gaming, where being an open gamer was usually tantamount to social suicide.
FFVII was a world so vast it literally leaked into, and overlapped with the real world in a way that nobody except those that where there when it was first released, and took part in that experience, can truly appreciate.
That's why it's special - because unlike other great games - FFVII wasn't just a great game - it was a phenomenon, like other giants in popular culture, whether we're talking Lord of the Rings, Harry Potter, Star Wars, or The Matrix.
Whether you liked the game or not - no other RPG, and I'd argue perhaps no other game has been a phenomenon to the same extent in that same vein (except perhaps World of Warcraft as much as I loath the game), and perhaps, as the medium has changed, no other game truly will.
I'd argue this makes FFVII special - not just to me - but special period.