The original! The one, the only! Metal Gear Solid for the Playstation! It holds such a special place in my heart as the place where it all started - Les Enfants Terribles, FOXHOUND, the cutscenes, the voice acting, the music. This is also naturally where it all started for me, watching in complete confusion one of those cutscene compilation videos and coming out knowing less than I did going in. It wasn't until I watched Vinny stream it a while later that i started to understand it properly and get deeper into the series (deeper than just being thirsty for Ocelot, i guess).
MGS1 is a serious contender for my second favourite game in the series (behind you-know-what), tied only with Snake Eater. I really enjoy the simplicity of this one, with the limitations of the hardware only making it a stronger game. The cutscenes never suffer from the characters being low-poly or lacking facial detail, and the strength of the cinematography, the atmosphere, and the voice acting makes it easy to forget the characters look so graphically primitive.
Another result of the game's limitations is that Metal Gear Solid manages to be perfectly concise, never succumbing to the same temptation that plagued later games to make cutscenes last far longer than necessary. Even MGS3 has cutscenes that leave my attention wandering, but MGS1 kept me transfixed, maybe only stumbling a bit in one or two of the powerpoint presentation cutscenes, but even these are kept brief.
The same goes for the story and pacing, the latter of which I'd argue is absolutely flawless. There aren't any moments that feel rushed or time that feels wasted. I have to praise the tail end of the game in particular; where after a busy start meeting an ever-growing cast of characters and a middle interspersed with equal amounts of tense sneaking and humorous dialogue, things turn eerily quiet. After the torture, the potential loss of Meryl, and the sombre death of Sniper Wolf and the switch to disc two, the gameplay turns relatively calm, and a lot of time is spent in elevators receiving updates from "Master Miller" about Naomi, and the real drama of Metal Gear Solid starts to unfold.
In terms of gameplay, of course Metal Gear Solid comes across as rather clunky these days. But I've never found things like the lack of first person aiming a deterrent, especially since the game is designed around this absence and rarely does it feel like it would add anything particularly useful (gestures vaguely at Twin Snakes).
My biggest issue with the game is really a lack of consistency in gameplay, something that would end up being carried forward into most of the following titles. The amount of stealth action in what is intended as a stealth game ends up significantly limited, due to a lot of interruptions by action-focused set pieces. I don't mind all of them, and it's certainly worth breaking up the intensity of sneaking around with more lively encounters, but I'd argue that's what the bosses are for. Even this I could criticise, why is Vulcan Raven's the only boss fight that makes use of the combination of hiding and making use of Snake's varied arsenal that the rest of the game is built on?
Small complaints aside, Metal Gear Solid really does deserve its place in history as a masterpiece. For it to have done everything it did all the way back in 1998 is nothing short of amazing, and it still stands up briliantly as an individual game in its own right, even without knowing all the complicated twists and turns of the lore in the games that followed.