Louis from Ghostbusters was a great character. If the 2nd sequel finally comes out, I really hope he's part of it.
One guy misses Rick so much as he wrote a song about it, see below.
From the mentalfloss post:
The short answer is: he retired in 1997. He lost his wife, Anne, to liver cancer in 1991, and later said: “I’m a single parent and I just found that it was too difficult to manage raising my kids and doing the traveling involved in making movies. So I took a little bit of a break. And the little bit of a break turned into a longer break, and then I found that I really didn’t miss it.” He didn’t completely retire from show business, though, as he released a country music album in 2005 called The Agoraphobic Cowboy.
Clickable link -> http://www.youtube.com/watch?v=J-7e70uNq5o&feature=player_embedded
(no copyright infringement intended)
Source -> http://www.mentalfloss.com/blogs/archives/94031