4. Kraven the Hunter
The first two acts of Marvel's Spider-Man 2 led up to this. Throughout most of the game (or until Venom entered the scene anyway) Kraven was the driving force behind all the chaos that unfolded in New York City. His search for a worthy adversary pushed him to commit despicable actions such as killing multiple villains that Peter Parker faced in Marvel's Spider-Man for PS4. As such, players grew to either hate him or love him (maybe a little bit of both), so having the chance to finally confront him in a duel was extremely satisfactory.
There are many layers to Kraven's boss fight. He can turn invisible and attack Spidey from behind, he can climb the branches of nearby trees and shoot from afar, and he can even call reinforcements in the form of robotic dogs. As if it wasn't enough he can also throw smoke bombs to stun Peter or set land mines across the fighting arena. It is a challenge to face Alexei Kravinoff, and rightfully so. He truly feels like the world's greatest hunter.
What makes this fight more interesting is that, by this point, Peter Parker's mind is fully hijacked by the symbiote. He's tired of Kraven's reckless actions and wants to put a definitive end to them. This is also a point in the game where players will have unlocked most of the black suit's powers and attacks, giving them greater aid in combat.
Unfortunately, Kraven knows high-frequency sounds are the symbiote's weakness, so right in the middle of the arena he set up a bell he'll constantly ring to stum Spider-Man. Players' attention will be divided between Alexei, his robotic dogs, and the ringing bell. It can be a lot, and it wouldn't come as a surprise if the fight is repeated multiple times until Spidey gets the victory. However, when that finally happens, you'll truly feel like a powerful hero.