Though the following games in the series did improve the gameplay (Hanging, shooting in first-person, Camo, CQC etc.) and of course graphics, the first MGS still has to be at the top for me, no doubt.
Oh and for the record MGS4 was awesome. Didn't take me that long to finish surprisingly. And the boss battles weren't as hard as they were in MGS3, but it was still a good game. You can really tell it's the end in the final conversation after the credits. Sucks that Snake has to go out like that though.
There was an article that came out that said David Hayter (Voice of Snake) really wanted Hideo to kill off Snake at the end in the cemetery. Saying how Snake would never allow himself, with the mutated Foxdie, to make the selfish choice and spare his own life while endangering others. I believe Hideo's response was that it humanizes Snake, which makes sense I guess, but I would have to agree with Hayter. Either way I still enjoyed the ending. Especially with Big Boss and Snake reconciling. Wasn't to happy on what the Patriots actually were though. That was kind of lame.
And I usually try not to geek out this much, but with MGS it's worth it.