1. MGS3; Probably the best plot and writing in the series. This game was incredibly rich, with hours of optional conversations over the Codec, collectables, sandbox possibilities in certain areas, lots of really cool special gameplay sequences (First person view in cinematics, the ladder, The Boss' execution, Snake's dream, etc.). It has also the biggest amount of great boss fights in the series (The End, The Sorrow). Soundtrack (
Snake Eater !) and overall 60's atmosphere were just too cool.
2. MGS2; I often have a hard time ranking MGS2 and 1 over one another. This time I'll take 2. I loved the idea behind the game, an enormous, nearly philosophical joke on the players. The plot could be a lot less convoluted, but that's part of the charm. The whole Solid Snake Simulation, that's in fact Selection for Societal Sanity, that's in fact... Just wow. It's so silly and brilliant at the same time... Plus :
mesmerizing soundtrack from Hibino.
3. MGS1; Total respect for the first Solid, a very important game in our medium's history. Simple but great action story, full of twists and turns, introduced great stealth gameplay, memorable villains (Psycho Mantis, Sniper Wolf) and Kojima trademark out-of-the-box game design (Merryl's frequence, Psycho Mantis again). Having replayed it recently, however, I must say I appreciated a little bit less some scenes and gameplay sequences, but it's still a great title.