Okay, so let me just start off by saying that all of the villains used in previous Spider-Man movies are off the table here for already being used(except for one but we'll get to that later). Now remember before you post a mean comment this is MY list and my opinions and if you disagree, tell me who YOU want to see on the list. And I know it's not CONFIRMED that there will be a Marvel Spider-Man reboot but I'm just saying if there is, this would be my list.
Shocker has really been underrated for a LONG time in the Spider-Man comics and tv shows. Pretty much only being used as a throwaway character just to fill in some time or just for the sake of adding in another battle. But I believe that if done right, Shocker could be one of Spider-Man's coolest movie villains. Take away that stupid quilt costume and give him some awesome new threads. Then all you have to do next is just make him as cool as possible and BOOM, you have the next big Spider-Man movie villain. Fan films all across YouTube have proven that Shocker can be a pretty sweet character. Now if a bunch of young filmmakers can make him look awesome, I'm sure a big budget studio can.
4. The Scorpion
My next villain on the list is Scorpion. Imagine this, Spider-Man is swinging through Manhattan and looks down below only to see a man in a mechanical scorpion suit(like the suit above) with a GIANT mechanical tail, just tearing up the streets. Now wouldn't that be a cool fight? Just think about all the cool thinks you could do with Scorpion visually and fight scene wise. Can't you just picture Scorpion smacking Spider-Man like a baseball with a baseball bat with his giant tail?
3. Kraven the Hunter
Kraven the Hunter, all the possibilities you can have with him. There are a lot of great stories you could tell with Kraven. The best and most memorable one being, "Kraven's Last Hunt" which is a story where Kraven shoots Spider-Man multiple times supposedly "killing him" and making a Spider-Man costume in which he runs around killing people in. We later learn that Spider-Man was not killed and Kraven buried him alive! Now wouldn't you like to see a story like THAT on the big screen? You could totally fool the general audience(the people who don't read the comics) with Spider-Man's "death".
Now Chameleon would be an interesting character to do. He can look like anyone he wants to meaning if he finds out who Spider-Man is, he could potentially ruin his life by doing things under his name. Chameleon also could mess with Spider-Man's head a bit by making him look like characters such as Gwen Stacy and Aunt May. Messing with his mind, not all fighting has to be physical.
My #1 pick for a villain to be in a new Spider-Man reboot would have to be Mysterio. I've been begging to see this character in the films ever since Spider-Man 2(the first trilogy). This is another character that could totally mess with Spider-Man's head. Mysterio can pretty much make anyone see anything. Now while they probably wouldn't go with the classic fishbowl head costume, I could see them going with the ultimate comics version(in the picture shown above) due to it looking not as... goofy. But they could pull off the fishbowl if they wanted to, I mean they are MARVEL STUDIOS.
I don't think I'm the only one who would want to see Mysterio messing with the web head's... head and using that as his advantage in the fight!