(I have visited this site often, and now I have decided to try to write my own article. This is mostly a test so please forgive any formatting errors.)
Now that Spiderman is going to be in the MCU, we now have a chance to see villains that were too weird for the previous Spiderman movies, but would fit right in the MCU. While we can also get more accurate versions of previous characters(and hopefully a version of the green goblin without an exo-suit and hopefully with an actual Halloween theme this time), characters like these would be better for his first outting in the MCU.
A character who has the ability to change his appearance, this enemy of Spiderman may not be the best choice for the main villain of a film. But he was one of Spiderman's first costumed villains, and could definitely make an appearance in one way or another.
2. Kraven the Hunter
Another villain of Spiderman's, this guy actually is a friend of the chameleon. He is a skilled hunter who tries to hunt down Spiderman. He could easily see Spiderman on the news during civil war and decide to try to take him down for sport.
Another villain of Spiderman, Mysterio is a master of illusion and originally tries to frame Spiderman. Although he definitely isn't as much of a physical threat as some other villains, he could be a welcome change from the type of villains we have been getting in the previous films.
4. Madame Webb
A supporting character of Spiderman, Madame Webb is a clairvoyant who helps out Spiderman from time to time. Although she is probably not going to be in the reboot, Raina in Agents of Shield turned out to be clairvoyant, so it isn't too big of a stretch to assume there could be others.
5. Scarlett Spider(s)
Although there are a couple clones of Peter Parker in the comics, the two most prominent are Ben Reilly and Kaine. Both of them go on to take the identity of the Scarlett Spider, although in the MCU the Scarlett Spider doesn't have to be a clone at all. Another vigilante with the powers of Spiderman, but a different approach to crime fighting could be interesting. Or Peter himself could take up the mantle after Spiderman is disgraced or unmasked in civil war.