Humanoid gannon in ocarina of time (reflecting those energy bombs was kickass).. and it disgusts me that games still havent learned how to do good real time combat from this game. (but anyway lol)
Psycho mantis and Sniper wolf (metal gear solid 1)
Final Showdown with bowser (both Super mario world and Mario 64)
Ninja Gaiden (xb0x) leet nunchaku boss was really fun
Gekido (ps1) End boss battle [awesome beat-emup game btw]
Quake 3 Arena - Xaero (railmaster 😄 )
Metroid Prime - The solar plant monster (I just thought it was neat)
Twisted Metal 2 - Minion and Darktooth (too cool)
Guardian Heroes - Sega Saturn - Those celestial crazies at the end XD
Resident Evil 1 (ps1) - The Snake , The Tyrant