My mind has been blown to smithereens by literally playing his games during the course of my life - playing MGS trilogy annually is kind of a Christmas tradition for me. It is simply my favorite videogame trilogy of all time.
The first time I fought against Psycho Mantis, I simply marveled the genius behind the fight. MGS2 was way ahead of the curve in almost of all of the aspects - smart texturing work, AI squad tactics, pinpoint pointer shooting accuracy, the still amazing weather effects, cue to the future of information warfare and fake news, VR missions, realtime cutscenes which I can't believe were possible on PS2 during its early stages, the score by Tappy/Harry Gregson Williams/ Hibino, superb VR missions, crisply written dialog and narrative - I still discover something new during my annual playthrough. MGS3 broke grounds by pushing PS2 to its limits, details such as the way the bullets rustle leaves during enemy skirmishes, realtime cutscenes that still hold very well today, probably the best boss fights in the series, great story, score, tight controls and that Hideo Kojima touch. I still remember the fight with The Sorrow, I had no idea on what to do and then I realized - these are characters that I have killed over the course of the game.
Kojima, is an auteur and a master of his craft.
Bonus edit: I recently discovered by accident (epsxe mis-configuration) that MGS1 detects if the player has a monoaural TV set during the fight with Hind D. Video here (not uploaded by me) https://www.youtube.com/watch?v=TzG8Sty9veI