It is a well-established fact of daytime drama life that actors who play dual roles win Emmys, (see David Canary, Julianne Moore, Anne Heche, Martha Byrne, Jennifer Landon, etc...) or at least receive Emmy nominations (Eileen Davidson, Thaao Penghlis, Michelle Forbes, Finola Hughes, etc...).
It is also a well-established fact of daytime drama life that the better, showier and more scenery-chewing role tends to be that of the "bad" twin.
Ellen Wheeler joined the cast of Another World to play Marley Love, Donna's "sister," in 1984. But the actress didn't really make a substantial splash until Marley's long-lost twin, Vicky, also played by Wheeler, returned to town, leading to the reveal that both girls were really Donna's illegitimate daughters.
When Anne Heche took over the parts in 1987, Marley all but disappeared from the screen, as the flashy, trashy Vicky began to dominate storyline more and more.
Jensen Buchanan stepped up to the plate in 1991, and while hers was a kindler, gentler Vicky, her Marley, in comparison, failed to make much of an impression.
Until, in 1991, Marley decided to risk her health -- both mental and physical -- in order to try and give her fiance, Dr. Jamie Frame, the biological child she was certain he desperately wanted. (Despite -- or is that because of -- the biological child he already shared with the more scene-stealing Vicky.)
Marley stole Jamie's prescription pad and began self-medicating to the point where her mood swings threated her and Jamie's relationship.
On the October 23, 1991 episode, Jamie finally calls Marley on her erratic behavior and, in a fantastic scene toward the 25 minute mark, the formerly meek and docile Marley un-spools and lets Jamie have it in a tirade worthy of... Vicky.
Watch that entire episode of Another World on Hulu.com, here!