Peeps are always the first to come to mind for me! But I also like the increasingly hard to find chocolate covered marshmallow bunnies and eggs---but the eggs MUST be in the cardboard egg crates not those nasty styrofoam ones...there is a difference in the taste.
Walmart used to carry my absolute, all-time favorite...the Heavenly Hash egg. It was a large, soft creamy marshmallow egg with and almond or two atop this marshmallow and covered in milk chocolate...I think it may have had a soft caramel in there, too. Delicious!
Dove used to have a chocolate truffle egg, too! About the size of the Cadbury egg, but when you unwrapped it, it was really 2 pieces. Has anyone seen these lately? My family loved them.