The Amazing Spider-Man 2 (2014) has been doing nothing if not hinting at the introduction of the [Sinister Six](movie:1274281) for the upcoming installment and probably future ones as well. The original Sinister Six consisted of Doctor Octopus, Electro, Sandman, Kraven the Hunter, Vulture and Mysterio. I love the idea of the evil team on the big screen, but I don't love two of the members of the current line-up that they're using.
Those two are Rhino and Green Goblin. I have nothing against these villains, except that I think that Goblin has been overused due to Sam Raimi's trilogy, and I'm mad that Marvel had to give Rhino a huge mechanical suit instead of using his comic book origin where an experiment boosted his strength and speed, but both of these villains were only in one out of ten incarnations of the Sinister Six. As most of you know, the trailer showed a glimpse of Doctor Octopus' mechanical arms, and Vulture's wings, who are both recurring members, with Doc Ock being most often the leader of the team. Electro's actually been part of the Sinister Six more than anyone else, so his inclusion is a must. Here are the villains that I think are more qualified to be the other members of the team.
Shown often in the various Spider-Man animated series' and introduced to the big screen in Spider-Man 3 (2007), Flint Marko has been part of the Sinister Six a total of six out of ten times. Besides the fact that he's been used in a film before, I like Sandman a lot and he poses a great threat to Spider-Man.
A master of special effects, Quentin Beck was a stunt man and amateur actor until he realized that his expertise in creating illusions could be used for criminal purposes, pitting him against Spider-Man. Mysterio has been in five out of ten incarnations of the comic book team, and his illusions have bested Spidey more than a few times. Mysterio is smart, resourceful, and cunning. He may not be as interesting, but I like him for a movie villain more than Rhino or Green Goblin.
3. Kraven the Hunter
Though he was only part of the team once, that one time was part of the original formation of the Sinister Six. Though he's not necessarily a villain to the public, his maniacal need to hunt big game makes him want to kill Spidey to prove that he is the greatest hunter in the world.
The only villain I'm including that wasn't part of the original team, but I've already said before that Shocker is the villain I want to see most in a Spider-Man movie, and a Sinister Six inclusion is the perfect opportunity. Though he's only been a member four out of ten times, Shocker's sonic, air-blasting gauntlets are a great asset against Spider-Man and his intelligence helps to make him a powerful enemy. I think that introducing him would be a great move on Marvel's part.
Unfortunately, [The Amazing Spider-Man 2](movie:508593) makes it look like Goblin and Rhino are here to stay, but if they, Electro, Doc Ock, and Vulture are going to bring the Sinister Six to the big screen, then who's #6? Could they re-introduce Venom? Possibly introduce Kraven the Hunter? Who do you want as the sixth member? Comment your thoughts.
(Research Source: Wikipedia - List of Sinister Six Members)