Eve will literally retrieve anything. Her go-to seems to be a medium sized orbee ball or a tennis ball, but every now and then she'll bring me a chuckit flying squirrel or a wubba.I am loathe to buy those, because she kills them quickly, but she has sooo much fun with them.
Her actual favorite toy to play with, ever, is this blue hartz football that I got her at Walgreens at the beginning of the year. It's the loudest, most obnoxious squeak ever because it's filled with soft foam, so every time she bites it or adjusts her bite, the toy screams and squeals. My head can seriously only tolerate a couple hours of that toy every day.