One of those actors, who left a lasting mark ... who played one of the most memorable patients in Grey's Anatomy history. We're talking about Denny Duquette, the unforgettable heart patient ...

Here are 10 actors who guest starred on Grey's Anatomy that you might have forgotten about, ranked. Your comment has not been saved ...

But do you remember the beginning? The series revitalized Patrick Dempsey's career and made household names out of the Season 1 cast. Grey's Anatomy was the show you had to watch every Sunday ...