Red Mango FTW!
Actually, there's a place at the Topanga Canyon Mall called Bare Naked Yogurt that's better than either of them. Upstairs at the entrance to the food court.
It's got a very yogurt-y taste, almost lemony.
I son't go there just because its soooo over-hyped right now. Golden Spoon is just fine for me thanks.
I'm a big fan of Menchies yogurt in North Hollywood on Laurel Canyon. Self serve frozen yogurt and self serve toppings. So good.