Are you seriously going to discuss about it? The answer is clear: Norman Osborn/Green Goblin. I'm quite pissed with Doc Ock for the whole "Superior Spider-Junk" thing, but that's just one big thing compared to Norman Osborn's long list of "hits". Even during "Superior Spider-Junk", Ock had to revive the one true Spider-Man because he realized he couldn't defeat Osborn like Spidey did. And in the last issue with his cloned body, he turned back completely into Doc Ock to defeat "Spider-Nor-Man". The combination of insanity, cruelity, personal vendetta and a lot of stinky money and resources makes Norman Osborn the ideal arch-nemesis for Peter Parker/ Spider-Man.