Draco in Leather Pants: Plankton. In this story, he is treated as a protagonist who is just misunderstood by everyone and is bitter about his failures. Here, he is honest about his plans to redeem himself and is not anymore coming up with another ruse to get the Krabby Patty formula, something he as pursued throughout the series. It's hard not to feel sorry for him here.
Wangst: Plankton angsts about his previous friendship with Mr. Krabs and his bitter failures in life. All these things drove him to suicide. Even if the fic is well-written for the most part, the first few chapters might come across to some people as wangst in contrast to the usually jovial tone of the canon. However, Plankton later on does do something about his problems after The Flying Dutchman gave him the second chance.