This is me being selfish but Feraligator. It's the only starter I don't have a really good one of. Since it's clear here nearly all the time the grasses and fire types were easy to come by.
I lucked out and caught a decent mudkip when I was out of state for the Holidays. I hatched a 96% Blastoise a loooong time ago. So raids would be the easiest way for me to get a good Feraligator to add to the bunch.