My five favourites:
1. Palpitoad: He is cute, strong and always battle good(except from the Roxie battle but that was because the writers wanted Pikachu to shine for the thousand time).
2. Totodile: He is so funny when he dances.
3. Torterra: Torterra is a cool pokemon with good moves and great power. He failed so much during the last episodes only because the writers wanted Infernape to shine.
4. Donphan: I liked Phanpy and I like Donphan too.
5. Squirtle: Squirtle is cute and cool and he is aweome during the pokemon race when Ash rides a Ponyta/Rapidash.