First and foremost I would choose Vince Vaughn (The Lost World and Dodge Ball) to play Peter Venkman.
Secondly, I would choose Kevin James (Grown Ups and Paul Blart: Mall Cop) to play Ray Stantz
Third, I would bring in Orlando Jones (Evolution) to play Winston Zeddemore.
With David Krumholtz (Harold and Kumar/ NBC's original series Numb3rs) as Egon Spengler.
As for the supporting cast, I would choose Eddie Kaye Thomas (Harold and Kumar/ American Pie) as Louis Tully.
Alyssa Milano (Charmed/ Ghostbusters the video game) as Dana Barrett.
either Julia Louis-Dreyfus (Seinfeld/ Michael) as Janine Melnitz
or
Eliza Dushku (Buffy the Vampire Slayer/ Angel)
Finally, Neil Patrick Harris (How I met your mother/ Batman under the Red Hood) as the Mayor or guy who's working against the Ghostbuster (a Walter Peck type Character)
I would then choose Dan Aykroyd, Harold Ramis and Bill Murray to write the script... Aykroyd and Ramis would keep it true to the original, and Murray would make sure that it's absolutely the best script possible before the film is made to absolutely please the fans.
That's my Fan Cast, Let me know what you think and if you would make any changes.
About The Author:
I have a huge collection of both movies and comics... As a kid and teenager I collected Marvel but within the past few years I've mainly gotten into DC Comics particularly Superman, Batman, Green Lantern and Firestorm. Other favorites of mine are Outburst and The Ray. I've recently started getting back into Star Trek which TNG was one of my favorite shows as a kid. I'm married to a beautiful woman named Elizabeth have 2 girls (Marissa 9 and Alexandria 2) and a son who's a year old named Edward. I own my own handyman and lawn care business. I can be reached outside of comicbookmovie.com @ http://www.facebook.com/LanternStorm1369