My favourite Johto starter is Totodile. As a kid, I was fond of Water types, so I nearly always picked Totodile in Pokemon Silver. Therefore, it kept growing on to me, and it's final evolution, Feraligatr, became one of my all-time favourite Pokemon. I love Feraligatr's design (Blue crocodiles FTW!)
Sometimes I picked Chikorita or Cyndaquil to give those a chance, but I never got to love them or their evolutions as much as I love the Totodile line.