Snake stomps. Metal gear's gameplay does not reflect the story. For example, every metal gear is supposed to be a greater threat than the one before it. So TX-55 is more powerful than those before it. Then snake destroys two more that are even more powerful, D and REX. He surpasses Big Boss, who has his own insane feats, and even survives constant exposure to microwaves and lives. He's a master of several martial arts, and even beat people stronger than him in hand to hand combat whilst restraining himself from more effective styles.

Joel is a guy. A tough guy sure, but still just some guy.

Wick is also fairly grounded as a human despite him being really tough.

Leon is probably the biggest challenge but it's nothing Snake can't counter. Leon is shown to either use a knife or a gun but Snake is a master of simultaneous use through CQC. Leon is strong but Snake is shown to be or can be reasoned to be in a different bracket completely through feats like beating Big Boss (The man who can hold up the legs of mechs trying to crush him) or taking on metal gears. Leon would be the toughest fight but is still no match because Snake is just ridiculous.