I've only seen Andrea Barber as Kimmy Gibbler, though I don't think she's been in much else, I heard she quit acting after Full House, but I loved her as Kimmy.
I'm sure part of Kimmy's hilarity was the writing, but a lot of it was definently the impeccable acting of Andrea Barber. She portrayed Kimmy with great expressions, vocal and facial, and was such an annoying sweet heart, you couldn't help but absolutely adore her. I adamantly believe she was the most hilarious character on that show. And while I respect, and understand, her decision to quit acting, I would've enjoyed seeing her in other things.