Marcia Brady (Played by Maureen McCormick)
Marica was the eldest of the Brady girls on the ‘Brady Bunch’ and was pretty much the perfect teenager. Sure, she was an overachiever, but she was friendly and cheery. Marcia was the girl who could do no wrong.
Source: picclick
She was very popular among everyone at school because she was pretty, smart, and everything she did was interesting. Hence the “Marcia, Marcia, Marcia!”