McGinley has a reputation as a show-killer for appearing on TV series shortly before they get canceled, although he lasted six seasons as Marcy's new husband Jefferson D'Arcy on "Married… With Children." Still, let's hope his show-killer powers are no longer potent, since he popped up last season as Mel, the head writer on Megan's soap opera who tried to rope Don and Megan into a "grass"-fueled foursome.
The halls of Sterling Cooper & Partners have been filled with a lot of familiar faces lately. Here are more than 20 "Mad Men" guest stars we recognize from previous roles in TV and movies. — Dave Nemetz, Yahoo! TV