I just got found out that he does because now and then they will either flirt or save each other. In Sonic X you can actually tell he liked her because he saved her and also kept the shell bracelet he had fixed. Amy gave it to him and Eggman crushed it so she beat up his robot. Sometimes Sonic will complement on the way she fights. In Sonic Boom both of them show a lot of interest in each other because Sonic saves her a lot and he is always worried about her. In one episode Tail's robot read Sonic's mind and the robot said, "I care for your well-being" and then Sonic smiles when she smiles at him.