Here is the First Series figure line. This series was the closest in look, and design to the cartoon show. Each figure came with their own ghost to bust. It also came with an awesome proton pack and neutrona blaster. These figures are the most valuable and most sought after. With most in the $50 dollar range MOC (Mint On Card).
The first series cards had the most variants. The European first series featured the most detail with a blue base and a detailed background highlight. The first US. card sticks to a simple blue background no highlight detail. The 2nd US. card and most common, has a more purple color to the card with with a lighter purple highlight.
Since this was the first produced and the line that most resembled the show. The First Series Heroes are arguably the most popular among fans. Below are scans of our favorite GB's in order Peter, Ray, Egon, and Winston.
Back of the Card
Fright Features (1988)
Here is the Fright Features series. Probably the most successful of the RGB Toyline. It featured an inovative way of showing facial expressions on our boys in grey. Sqeeze the arm and see what happens. This line brought about the tradition of featuring far out costume and color designs. The look and design from here on out in the RGB toyline was never featured on the show.
These are some of the easiest to find MOC or loose. If you find them loose. Look out for a broken tie on Egon, and a broken left arm on Winston they seemed to be weak points in the design.
Back Of The Card (from GBAF)
Screaming Heroes (1989)
Here is the Screaming Heroes series. These figures came with a ghost that you would attach to the figures stomach and when you would wind up your hero the figure would make a "Screaming" noise. This series finally introduced a Ghost Trap, and P.K.E Meter with Peter and Egon getting those respectively.
An interesting side note is that Peter's weapon was rehashed and used in Kenner's Star Wars "Power of the Force" line.
Super Fright Features
Super Fright Features (1989)
Here is the sequel to the successful Fright Features series. Each figure featured the GB's in odd space suits and added new facial expressions by pulling a lever on the back of the figure. Do to the bizarre and quirky nature of this line. It didn't match the popularity of the previous lines. This was also the last human line to use non first series figure molds.
Back of Card (from GBAF)
Power Pack Heroes
Power Pack Heroes (1990)
This series broght back the fan fav First series molds. They each came with a Power Pack that had its own "ghost catching" action. This line introduced Louis Tully to the RGB toyline. While Janine was given a traditional mold for the first time, it was her last appearance in the the RGB toyline.
An interesting fact is that a few years after the Power Pack Heroes were released. Kenner reused Peter's Bouncin' Bazooka in their Batman TAS toyline, with the Pogo Stick Joker.
Aside from different color schemes and lack of string, its the same accessory
This series of figures was the largest. Do in part to the addition of Louis and large power packs. This was also the last line to feature anything besides the figure/proton pack dynamic.
Slimed Heroes (1990)
Here is the Slimed Heroes series. It brought back the famed proton pack. They each came with a ghost that would squirt cold water which would give the effect that the Ghostbusters became slimed. This line also gave each figure an odd mask, except Ray finally got a pair of removable Ecto Goggles.
Each figure came with the classic Proton Pack molded in "glow in the dark" plastic. Each figure was given a mask identical to their face to fully immerse themselves in the "glow". They also came with reused ghost molds from previous lines. A new feature was the proton stream was molded to fit the companion ghost. So the steam would effectively capture the ghost.
Even with this cool series. Teenage Muntant Ninja Turtles was just too popular. This was the most limited, and last official release of the RGB toyline.