I normally cringe when these type of blogs pop up (Hey, while we're at it, let's play who would win, just like last week and the week before that! >.>) but I'm saddended by the scope of predictions for the new Spider-Man series, so it's time to show you little kiddies how to really dream up things that will never happen.
I know everyone wants Marvel to take over and reboot the character in MCU continuity (just like every Marvel character still out there), but that isn't happening as long as Sony have a say in it. With that being said: Stop thinking in a confined, trilogy-based scope. Andrew Garfield is not only a better actor as Peter Parker, but he can look the part for years to come. So do the Harry Potter thing. Make this a 6-8 movie series.
There are a few main plot points I'd like it to hit. Firstly, Osborn doesn't need to be the main villian for sometime. Have him be a behind the scene's guy. He doesnt have to pop in to the villian spotlight till like the third movie. Even then, make him secondary. Have him show in the end like a Goblin cameo. In #4, have him fullfill his destiny and kill off Gwen (or make it gritty and make it Peter's fault). #5 can have Peter dealing the massive guilt and depression from Gwen's death, and growing closer to MJ (Introduce her to begin with in #2 or #3 maybe). #6-7 will feature Peter and MJ's budding romance and all that mushy crap.
Finally, I think a version of the Sinister 6 needs to show for the final films. Maybe show the workings in 7, but have them show as the villians in 8. If they need to, do the Potter/Twilight thing and split the last movie in two to make 9.
There's a few other things to throw in. I feel that the organized crime world needs to make some appearances. Not like starring as a film's main villians, but just showing throughout the series. Maybe along the lines of the Scarecrow cameos in the Dark Knight trilory, or even smaller. Have paper headlines or news reports playing in the background that feature stories pertaining to Hammerhead, Stoneface, Wilson Fisk, or even D.A. Tower.
I really don't know about the villians to use. The classics are always up for grabs: Sandman, Electro, Shocker, Doc Ock, Green Goblin (obviously), Rhino, Vulture, Kraven, Scorpion, Mysterio, Chameleon. The Sinister Six should contain a villians from the previous films, but also a new villian or two to keep it fresh. And Spidey needs to kill at least one villian in one of the movies.
And no, I didn't list Venom and Carnage. I know that's terrible, but I feel that they are too big to put in if you want to keep the series balanced and good, no matter how awesome an R-Rated Spidey vs Carnage movie sounds.
And that, kids, is how you make a kick-ass movie series.