Clash of the Titans (1981), which interpretated many aspects of the Perseus myth loosely, redefined the image of Medusa as much more monstrous (to having a serpent-like body along with the traditional snake hair). You can see Clash's influence on many modern pop-culture depictions of Medusa - including the video games (Castlevania, Monster Party, God of War) - below.
Perseus holding Medusa's Head - Clash of the Titans (1981)
Head of Medusa - Clash of the Titans - 1981
Medusa in her lair - Clash of the Titans - 1981
Medusa from the COT Remake - 2010
Super Castlevania [SNES] - Boss Battle
Monster Party [NES] - Boss Battle
God of War Concept Art [PS2]
God of War Concept Art [PS2]
God of War Concept Art [PS2] - *Possibly Stheno, one of the other 2 Gorgons