I'm having this MGS3 kick recently and have been wanting to play it again, if only to judge its story.
I also want to play MGS2 again since it was the tits on the Vita. Really a solid fit for a handheld.
And then there's MGS4, which I'll pay one day when the cutscenes' lengths don't intimidate me so much.
So with MGSV's prologue out, what's your favorite Metal Gear Solid game?