3. Dane DeHaan - As Harry Osborn (The Amazing Spider-Man 2)
Dane DeHaan is a fantastic actor who has totally blown up in the last 18 months, starring in a string of great movies and pretty much cementing himself as a future Oscar winner. However, his casting as Harry Osborn in The Amazing Spider-Man 2 just doesn't really hit the mark. It would be silly to compare him overtly to James Franco's take on the character in Sam Raimi's Spider-Man, because the visions of the character are, of course, going to be markedly different, but is the slight, inoffensive DeHaan really what we want as Parker's best friend? I suppose it really depends on what their angle is with the character; if Harry will eventually become the Green Goblin in this universe, then it's going to be strange seeing the thin-framed DeHaan in the costume, but if he's kept as a supporting character who stays out of any villainous costumes, then perhaps this just might work.