Design wise- Chimchar and its evolutionary line takes it
Cuteness- Chikorita and its evolutionary line takes it
Usefulness in their own game- Chimchar
Overall- Chimchar and its evolutionary line takes it for me. The nostalgic Chimchar gives me is incredible. I'm a huge fan of the Monkey King, and Infernape is literally based on that character. You got other characters also based on him like Goku from the Dragon Ball franchise, Son Goku, the four tailed beast from Naruto, Enma, the personal summon of the third hokage from Naruto, Jin Mori from God of High School, and much more.