Hmmm hard to say, definitely not Portable Ops.
1st - MGS4 - Just because it was the finale and is the best PS3 game i own.
2nd - MGS - First MGS game i played favourite PS1 game.
3rd - MGS3 - Another great game.
4th - MGS2 - One of my favourites but the story lets it down.
That is my order, except I think of MGS4 and MGS as 1a and 1b.
I am curious to see anyone think of a rational explanation to back PO as #1 MGS game. I thought it was going to get 1 vote
Human contact, the final frontier.