Metal Gear Solid is a samurai epic.
Yep, it totally is.
Whether this was Hideo Kojima's intention or not, the original Metal Gear Solid is very much a post-WWII samurai epic. Think Akira Kurosawa's most celebrated films or even Christopher Nolan's Dark Knight Trilogy. An epic is the story of the rise of a hero or heroes and a great journey undertaken, with strong thematic repetition and strong supporting characters. In a samurai epic you can also count on the protagonist to be a psychologically scarred, disgraced and even rather cynical warrior.
That's Solid Snake except he was redefined as a voiced protagonist and there were consequences for that choice. However, unlike space bounty hunters or those who raid tombs that one day find themselves with full voices acting, Solid Snake was a protagonist with his agency fully taken away and then given back in full to the players within the sane story. This is accomplished by way of the samurai epic, thus the specter of lost player agency was deftly avoided.
Much like Christian Bale is a terrible Batman on his own, Solid Snake isn't much by himself even with David Hayter's wry and perfect delivery behind it. To make Snake or Bruce Wayne more than who they are, it's the wisdom and insight granted along the way - be it from friend or foe - that allows the player or viewer to have something to ascribe to the protagonist and let it help them enjoy the hero and empower them. You're not so much interpreting and occupying Snake's mind as you are aligning your view of him with that of Meryl, Otacon, Psycho Mantis, Sniper Wolf or whomever you find most agreeable.
As these other character relate their stories to Snake, players may be given things they may identify with from that ally or enemy, then they just imprint that character's views on Snake to give him that extra oomph. He becomes more than a cranky man in a sneaking suit.
Most people, when pressed to describe Solid Snake will say he's "badass." It's quaint, but it's because they're unfamiliar with how to frame the story and how it made them feel beyond the empowerment. The samurai epic narrative is just rarely employed in games. No More Heroes also fits, though intent is somewhat different.
Anyway, the next time someone asks you what's so great about MGS, tell them it's because it's a samurai epic. Solid Snake may not have a sword, but he's certainly a samurai.
If they ask what MGS2 is, say it's Scream 2.
Just a thought.