(Egon) did not act in a major role after this film, although his appearing in a possible GhostBusters 3 was not ruled out. However, Ramis was a successful director in the 1990's and 2000's, starting with guiding fellow GB Bill Murray through 1993's "Groundhog Day".
His other directorial highlights include "Analyze This"(1999) and "The Ice Harvest"(2005) and "Year One"(2009).
Craig kindly wrote in to say that the he since played, of course, Dr. Betz (sp?) in "As Good as it Gets", the private doctor Jack Nicholson's character hires for Helen Hunt so that her son will be healthier and she can return to work.
Sadly, since this was originally posted, Harold Ramis passed away in the spring of 2014. Bill Murray paid tribute to him at that year's Academy Awards ceremony.