When spiderman put on the black suit it pretty much ruined his life as aunt may said "revenge is like a poison." well in a way it was a poison. for if spiderman hadn't gotten rid of the suit when he had the chance he could have avoided harries death in the film.
My least favorite part of the 3rd film was when peter did his symbiote strut. he looked like a guy who had too much to drink.
But he did redeem himself when he saved mary jane from venom. Although it was his fault in the first place that she was in this mess.
In all spidy made a huge mistake choosing power over right mindedness