Ha none of them lol. I am working on platinum in MGS2 currently.
You're in for a hard one. I'm going to try to platinum MGS3, I think that it's the easiest from all of them. In MGS2 you need to finish all the VR Missions, and they are hell harder than the ones from MGR:R (and even these are hard).
PlayStation Network: DarkEmigaru98 Youtube Channel: http://www.youtube.com/user/Emi3280