6. Brock Lesnar
No, this isn't just because his name is "Brock" and Venom's real name is "Brock Lesnar" - I actually think this could be an awesome casting if the human side of the character was more like the 616 version. Lesnar looks very much like the classic 616 version of Eddie Brock - both facially and in his build - and, although he has no real acting experience, playing a minimal and brutish role (if that's what the film-makers decided to go for) isn't really much of a stretch for someone who has played a character of that exact nature in the WWE. And he's freakishly big to the point that he would look monstrous next to Andrew Garfield, should Spider-Man appear alongside the character, so he'd be a monstrous foe even without CGI. That said, he's probably a long way from being able to carry an entire movie at the moment, so any potential casting would require giving Lesnar time to hone his acting skills somewhat but, if Sony and Marvel are prepared to be patient with the guy, it could be a stroke of genius (especially if he has a strong supporting cast alongside him to carry the load).