Last winter Kirsten was only interested in finding about 5 eggs or so. We put Little People Easter figures and raisins and goldfish in them last year; she got to the first Little People figure and was done looking for more eggs. This is the list I worked from for egg fillers this year, if you have any other suggestions please share them in the comments.
Toddler Easter Egg Filler Ideas
Small cracker snacks (ex. Teddy Grahams or Goldfish)
Cereal (I pick something she never gets that I think she'd like)
Fruit (blueberries, raspberries)
Coloring pages (folded)
Paint with water pages (folded)
Shaped Crayons (Triangles, Dinosaurs, Stars or any small chunky shape)
Fisher Price Little People figures (in bigger eggs)
Coins (Kirsten loves putting coins in her piggy bank, she was too young for this last year)
Kid washcloths, bath mitt or pouf (I stuck a Hello Kitty pouf in an egg last year)
Sample size bubble bath
Small cars - once they are past sticking things in body orifices
Mini dinosaurs (perfect size for easter eggs)
Rainbow Nest Counting Eggs - or similar counting objects
This year I went with stickers, hair ties, coloring pages, teddy grahams, yogurt covered raisins, chocolate covered raisins, kix, and froot loops (she hasn't had these before, I'm sure she'll love them).