Teresa

The best thing about this telenovela is that there aren't entirely good persons, even those who are "good people" (translation: Aurora and Mariano) act according to harmful ideas, out of jealousy or selfishness

Which makes it more fun to see what Teresa will do next, and just sit back and enjoy the drama. There isn't another show that embraces the conflict and the concept of soup operas than this one, with an excellent actress who exudes charisma with her character to top it all

Let's say the bad side is the narrative insisting that we should like the rich friend instead, despite the fact that she caused harm to other people as well and had a flimsy concept of loyalty.