Spider-Man 2 has a cliffhanger?
Doctor Octopus may or may not have drowned.
No. Harry finds his father’s arsenal when he throws the knife into the mirror. I don’t consider Spider-Man 3 personal canon. It’s not that big of a cliffhanger, but I’ve always found it interesting to think about.
It’s a sequel hook for sure, but I don’t think I’d really go so far as to call it a cliffhanger.