First off, I dislike Kraven. Never have. I don't like the idea of Tarzan coming into a modern-day city, trying to hunt down Spider-man. Secondly, Mysterio is incredibly underrated. It'd be awesome to see Bruce Campbell as Mysterio. He'd need no origin story - that could be left for Connors -. Master of illusions and all that would be awesome. Thirdly, Connors has been introduced through 2-3. So, Lizard is kinda a give me.
For Spider-man 5, like everyone else, I want to see Electro. He'd be a tough challenge for Spidey. And Scorpion is one of my favourite Spider-man villains. Electro hardly needs much of an origin, so like Lizard, it can go to Scorpion.