Easeros, definitely.
Uilus is next in line, with Ebilia coming last. The adult Ebbies just aren't cool/cute enough and I don't feel like constantly zapping them or stuffing them in my Rancher Shop where nobody looks. But the baby and middle stages are fine.
For all the seasonals, it goes like this though. Easero --> Iluvu -- > Uilus -- > Ebilia -- > Jaaku