This was a toughy, choosing between these three series, which to put where. So, I think I'll combine #3 and #2 together in this one. Also note that, as of right now, 3 = 2 = 1 for me. It is truly that tough of a decision.
While these games DID start off on the MSX with Metal Gear and Metal Gear 2, I'll be focusing on the meat of the series. The Solid Playstation games.
I'd be lying if I said there wasn't a year I didn't play through these games. I always play in the order of release, and I've done it every year since the release of Metal Gear Solid 2.
Everything about this series is phenomenal. The gameplay, the focus of stealth, choosing between combat and sneaking, whether to kill that guard who's blocking the door, or letting him live and finding another way around. The story is fantastic, up until the latter parts of Metal Gear Solid 4 with the BS "Nanomachines did everything D:" explanation, but I really don't mind anymore, because the characters are more important than the story of these games, I think.
Solid Snake - The "hero." Seen by others as mythical, but won't have any of it. Does his job because it's right and nothing more.
Revolver Ocelot - The series main villain. A triple crosser, excellent gunman, and devious plotter.
Raiden - The "rookie" soldier. Unknown to him until he is reminded by his adoptive father, Solidus Snake, he is a soldier of inhuman proportions. No augmentations like Solid Snake, and he killed like a demon. Being constantly reminded of his days as a child soldier, he is sent into a downward spiral.
These are just three of the characters I think about when I think "Metal Gear Solid." Seeing their stories begin and end was one of the best parts of the series, especially Solid Snake's story. I cannot wait to see the prequel with Raiden.
Probably the best RPG to ever grace this world. Again, not a year goes by where I don't replay one of these games, my most played being Final Fantasy IV and VIII. I haven't played IX as much as I've wanted to, but I just found it at a local store and am finally going to be able to play through it again.
Starting the series out, it had basically no story and no characters, but the gameplay, the fact that you were put in the boots of the Warriors of Light to save the world from a devious being, kept you playing. You wanted to save the world, wanted to fight on, to become stronger and slay that monster in your way.
As the series progressed, storyline and character development became more and more important. Final Fantasy IV was the first real game in the series to have an expansive storyline and character development. You felt like you were Cecil, fighting off your darkside to become a warrior of light. You felt the betrayal he felt when Kain sided with his mortal enemy, and the rejoice when he came to and realized who needed to be destroyed.
This, for me, was the beginning of Final Fantasy as it is today. Final Fantasy would go on to spawn an astounding nine more sequels, one of them in particular being liked so much that fans would rather a remake of it than a new game itself.
Constantly reinventing the setting, story, and characters, Squaresoft, and later, SquareEnix, has brought back the magic again and again with this series. I am always anxiously awaiting the next title, so long as it isn't another VII cash-in.