In 1986, about the same time RGB appeared on our TV screens, and the action figures started showing up in the toy section, West End Games released the first edition of the Ghostbusters role playing game.
GBI is now hosting scans of that first edition.
http://www.ghostbustersinternational.com/frightrpg.htmCredit to Peter Venkmen (with an "e") of GBCentral for scanning the pages, and to Rich Roy/Spengs for cleaning them up.
I have very fond memories of these books--I got that first edition for Christmas in 1986 along with the first series of action figures. From the GB fan perspective, that was the best Christmas ever.
Bonus:
Ectofiend of GBCentral posted scans of a semi-official module published in a gaming magazine c. 1987. It's "semi-official" because it was approved by West End Games, but Columbia wasn't involved (which is probably why the article is accompanied by...underwhelming fan art instead of official illustrations).
Most interesting to me was the list of equipment prices. Despite some painfully dated references ($4000 for a computer? In 1987 maybe...) it could prove a good basis; inflation versus the lower prices of technology could just about balance out.
http://forums.ghostbusters.net/viewtopic.php?t=12466West End introduced the second edition of the Ghostbusters game in 1989, under the name
Ghostbusters International. It used the GB2 logo, and did revise some of the rules. GBI has one sourcebook, the
Tobin's Spirit Guide, scanned and hosted on their site too.
http://www.ghostbustersinternational.com/tobins.htm