MGS3: Snake Eater: Best story and characters, great soundtrack, amazing attention to detail, one of the best games of all time. I only don't like the weird controls. It was the first game i used dual sticks for and i'm left handed, so aiming with my right thumb took a while to master...
Best port for me is the Vita one, and in the 3ds version the controls are actually improved and you can do the duckwalk!
MGS2 is my favorite game, but honestly I'd say that MGS3 is the best, if that makes sense? Like, I love MGS2 but it's rather annoying at times and I feel like MGS3 improved a lot.
I love the soundtrack of MGS2, its my favorite across all gaming especially "Can't say goodbye to yesterday".
Metal Gear Solid 4!
A lot of people prefer 3, although I feel like that may be mostly nostalgia. Sure, 4's story is almost at Square Enix levels of convoluted, but the gameplay is by far the best, the cinematics are great, the graphics are great, the music is great...everything is great! MGO2 is also the best multiplayer version in the whole series.
Fight me.
To actually enjoy MGS4 you have to play the other 3 games, or else It's confusing and the gameplay feels too segmented. I personally think it's amazing too, I had a great time playing it and the cut scenes, wow mind blowing, the graphics and animation still among the best there is. Never played MGO2
but most people seem to think its the best MGO...
By the way I have as much nostalgia for MGS3 as I do for 4, I played them all in order up to Peace Walker in 2013.
MGSV for me has the best controls and best gameplay and I do go back and play a mission or two. It's not the best because of the disappointing / badly written story and overall as a game it starts great but ends crappy and lazy. It should have been the best one...