Chocolate is the clear superior. The only permissible additions to chocolate ice cream is MOAR CHOCOLATE! Chocolate chips, chocolate sprinkles, chocolate syrup, brownie bits, and maybe even some m&ms!
I'm not against vanilla, as it makes a good base flavor for other additional flavors to be added to, but just straight vanilla?! Who would choose that?! That's like saying instead of a sandwich, you just want white bread. And the sheer number of people saying this... clearly I have delayed too long. I wish I had more time, but... it has to happen NOW, for the good of humanity!