Ugh Ok ninja i just read your comment so im going to answer both : Caterpie , Weedle , Magikarp ,Pidgey and rattata and many more But the highest rate is actually those poekmno with a Master ball :) . But what i wanted to say was, actually technically its the starters because if you get one your guaranteed it (breeding,trading first pokemon,etc.)or that magikarp you get for five hundred bucks in FR.