I'm very opinionated and have looked at the fan casts going, "Yes..no...maybe...not him..not her.....never....that could worke.......eehhh maybe.."
So here's my spin, regardless of what movie they're put in, this is casting in general, not for just one movie.
Thomas Dekker as Peter Parker/ The spiderman
Let me reiterate...him as Peter is embracing the more darker side of peter in a more realistic world cercumstance in which he is more traumatised about Uncle Ben's death, spiderman is what he'll use to lighten up the mood of Peter, until then, he's like what any Teen would be after death in the family thats beleived to be your fault.
For Mary Jane, Mary Elizabeth Winstead...OW..
Harry Osborn- Checkov, or Anton Yelchin...
I Have to confess I wasn't strong about my choice for Gwen Stacy- so I choose Danielle Panabaker
Steven Strait as Eddie Brock
Uncle Ben- Donald Sutherland
Aunt May- Jayne Atkinson
Norman Osborn- Neal McDonough
Doctor Octopus- Otto Octavious, head of Oscorp science staff to follow up Spectacular Spiderman story arch- Michael Emerson
For the lizard- Bruce Greenwood, i've always seen him as a Kurt Conners type myself
Kraven the Hunter- Karl Urban
Calypso Kravonoff- Sharon Leal
Max Dillon, con, highschool freind, work hand for Oscorp, whichever story arch fits, i choose Rami Malek. Aside from his creepy soudning name, he can really do well as the "OMg....I stuck my finger in a light socket and now i'm gonnna effing kill yah!" kind of thing. I've seen him in 24, and he can play a good electro, just as long as they keep him away from that rediculous costume, give him a trench coat, pale his skin, with veins going across it like lightning shapes.
Robbie Robbinson- Rondell Sheridan
J. Jonah Jameson- Clancy Brown (Come on, tell me you cant imagine him screaming "PARKER!!")
Captain Stacy- James Morrison
Timothy Olyphant as the Masterful Mysterio...