3. Spider-Man 3
Given how the first two Spider-Man films were elegant but samey affairs, it was admirable that Sam Raimi was going to try something a little more ambitious in Spider-Man 3, turning Peter Parker to the dark side and introducing a villain who actually had some pretty favourable qualities. On top of this, Raimi would tie up the loose ends and essentially conclude his franchise in suitable fashion, but the studio had different ideas. Producer Avi Arad insisted that Venom be a part of the film, and despite not liking the character, Raimi obliged, while also adding in Gwen Stacy and causing the film to become one overstuffed, over-ambitious mess. There's even a rumour that Saimi cast the bizarre choice of Topher Grace as Eddie Brock just to piss off Arad, but whatever the reasoning, there's no doubt that the film was an unmitigated disaster. And now we're stuck with this dreadfully cynical reboot. Great.