What Pokemon's did you grow to like over time, whether it's because their design warmed up to you, or their use in battle, or what have you? Mine has to be Hariyama, ugly looking Pokemon but warmed up to over time.
Blastoise. At first I thought, "Oh, hey, a turtle with water cannons." But later, I found out that he's extremely useful in battle.
It helps that in real life, he would also be extremely deadly as well.