Between all the games, my favorite is Metal Gear Solid, since its writing has so many interesting bits that they don't take place in Metal Gear Solid 3, but the latter offers a more interesting and memorable story than the original. Especially since in the latter, the actions that take place haunt the character and to an extent the player since they are the ones who must pull the trigger to end The Boss' life, and feel like spitting in the face of the CIA for what occurred.

However, in Metal Gear Solid, things like emotions, and the story itself is told through the characters. Otakon falling for Sniper Wolf and being emotional, wondering whether love can bloom in a battlefield can be a metaphor for some of Solid Snake's thoughts since he is at the time, falling in love with Meryl. However, Solid Snake is a cold blooded and haunted killer who can't really express those emotions, especially on the battlefield that was Shadow Moses, so Otakon, a more common person who hasn't suffered from atrocities and war, he works as someone to deliver emotional responses that albeit are silly, they are essential ones that Snake cannot comfortably express.

On Metal Gear Solid 3, the relationship between the characters is slightly worse than what it was in MGS, nonetheless it's good, but the relationship between who Big Boss interacts with it's always either limited, or you know that he's being played by EVA. On the other hand, it compensates by giving a mentor like The Boss and the most interesting codec calls in the series. From fun ones, to depressing ones and simple explanations of game mechanics and weapons, the codec is something people try to listen again and again without a stop simply because in MGS3 it's more awesome than it was in MGS4 or what it will be in the future.

But the codec had its moments in Metal Gear Solid, and it's even more fun how it literally breaks the fourth wall for you to find the codec number for Meryl. There are some interesting conversations, but they are mostly told via Miller or Nastasha, and they hold up for you to learn more about either Alaska or the guns you're using and the military systems.

So, I think hands down, Metal Gear Solid is superior due to its characters, storytelling, but albeit loses a little in the fact that the characters in the codec are more interesting in Metal Gear Solid 3, since most people never speak to Miller or Nastasha outside their automatic calls.

Now, for the worst game? I am confident that Koji Pro lost its track while making titles for the PSP. Portable Ops for example was an interesting game, but didn't offer that much on the table like Peace Walker did, I think it's unfair because Peace Walker upped the standards for PSP games in a sense, since it offered a whole experience, and not just another spin off or side story, it's an actual Metal Gear Solid title, on the PSP, and it's a great game, but yeah, for the worst in the series, Portable Ops+ is my choice.