You're pitting childhood friends against each other!
;-) I found out Sarah Michelle was homeschooled because of her childhood celebrity. Melissa Joan was her only friend, she'd ask her all kinds of questions about what school was like and imagined what it'd be like to go to a real school. I felt so bad for her when I read that...
Since I saw Clarissa Explains It All and had a crush on her long before I ever saw Buffy, The Vampire Slayer, i'l choose Melissa Joan Hart. I even wrote a Clarissa story back in my pre-internet days about the episode where she stole the bustier. ;-)