5. Psycho Mantis Reads Your Mind
This is one of the all-time great boss fights, but for more than just getting to hand Mantis a FAMAS-flavoured beatdown. A major part of it was the novelty of having to plug the controller into port 2 to prevent him from reading Snake's mind, but the focus on this entry is the buildup to the fight. Mantis will perform various feats of psychokinesis and telepathy in an attempt to intimidate his foe. For instance, in the Gamecube remake (The Twin Snakes), he creates the illusion of setting the room alight and making the portraits on the wall laugh. By far the coolest thing he does, though, is read the player's mind. He starts off by talking about how cautious Snake has been on his mission so far, and how well he has fared in combat - but it gets even weirder than that. If you have save data from other Konami games stored on your memory card, Mantis will mention them by name (in The Twin Snakes, Mantis will instead refer to Nintendo titles), thereby freaking the player the hell out and ensuring the ensuing boss fight's place in the annals of gaming greatness (skip to the 3-minute mark for this bit). Even if the boss fight itself was total rubbish, which it wasn't, the lead-up to it was so unbelievable at the time that it probably wouldn't have mattered anyway.