MGS games are the best there my favourite games on the playstation, i just yesterday completed MGS3 on European Extreme mode i havent played on it for ages since then my favourite character has always got to be revolver ocelot.
I also like the gta series my favourite so far was GTA III (3) all the gta games since gta 3 have been much easier. My favourite PC games are CS:S (Counter-Strike:Source), GTA:SA (Hot Coffee mod (rofl)) and most of the games you can get on steam.
XBOX game: Halo