Which sadly, besides the cool secret weapons and such, doesnt leave you much of anything substantial to do...
I'm a huge MG fan, and I will say that of the "newer" ones, my tier is MGS, MGS3, MGS4, and MGS2.
It was cool, but as time went on I realized that my love of the game wasn't for the one game and it's specific story as much as it was for the overall story and my own history with snake playing all these years. Especially that one throwback area....Oy... beautiful.
MGS4 just felt like it was throwing everything at me unnaturally storywise (like MGS2). Almost like it was trying to form a vocal encyclopedia and then let me play for a little bit while I process the story.
Especially now that I'm playing through Mass Effect, which MGS4 pales in comparison to, I hate to say.