Pidgey, Caterpie, Weedle, Spearow, Nidoran f, Nidoran m, Eevee, Clefairy.
Those 8 keep repeating the most in our neighborhood. I seriously have 138 Pidgey candy from 5 days of playing. Strangely enough we have no Rattata at all!
I don't mind the repeat Eevees though, I've now collected enough...