Cindy Isaacs spotted the first instance and reported it thus:
"On old repeat of The Golden Girls, which I do not usually watch, the episode revolved around one of the characters dating an actor who plays a costumed superhero on a children's TV show. One of the "girls" says "What kind of man walks around dressed in a cape and tights?" Another charachter replies "Marshall Herskovitz!". This comment is not explained. Later in this episode, a character asks, "So how's the (children's)TV show ?" The response--"Well, it stinks, but it's still better than thirtysomething!"There was a second instance, another reference to Mr. Herskovitz, which eludes me at this time (not a very difficult feat really).
Now, we've spotted two "crossover" actors in that Herb Edelman, who played Melissa's father, was a regular on The Golden Girls as Dorothy's ex-husband, Stan. Also, Dorothy's daughter was played by Lisa Jane Persky who played Sharon Berman, Elliot's first date after leaving Nancy ("whose forest is this?").
But other than that, we got nada, zip, zilch. Write in with your solutions!