I like MGS1 the best as a whole, but its gameplay hasn't aged too well. MGS2 on the other hand is a lot like MGS1 but I think it's better. It has more cutscenes, even to an extent where I think there's slightly too much of them, but its gameplay has aged much better than MGS1's. So my two favourites are MGS1 and MGS2, and if I have to pick just a single one, it's MGS2.
I also like MGS3 a lot, but it's a little bit too menu-heavy and its bosses aren't as memorable (as characters) as the first two games', so I don't think it's as good as the first two. And the rest? Well, they don't come anywhere near the first three, they all have some pretty big problems in some key areas.







