Short answer: No.
Long answer: Gameplay is decent, but there's never enough of it and you have to turn the difficulty all the way up for stealth to even matter, and even then it's just cardboard boxes. Don't get me wrong, I liked MGS1 and 2, but at the end of 2 I lost all faith in the franchise ever making sense again. That game has a fucking terrible plot and every new character and cutscene is an exercise in murdering my suspension of disbelief all over again.
Legacy and influence are the same thing, and I'm not sure I've seen either in any other games. What would that entail? Other games having a horrible, convoluted story that makes absolutely no sense? They've done that before, you know. Oh, I know, how about having some really weird issues with women [small](yeah, I agreed with Yahtzee's column for once, deal with it)[/small], 'cause games have done that before too. Then how about having more cutscenes than gameplay?
Well, there were tons of FMV games in the 90's, and you may notice that some of the bigger successes in recent times have been the games that AVOID the formula used in the MGS games. Even plot-heavy titles from BioWare and Obsidian dodge it by making dialogue largely skippable and interactive. Maybe the MGS games have some influence as a cautionary tale, yet somehow I don't think that's what you meant.
And again, because I can't stress this enough: The story is one of the worst in any game I've ever played, and I played the tie-in game for The Phantom Menace (please don't ask, I'd rather forget).