Shellder. She seems to ALWAYS have happy reactions, even if her HP isn't too high. It makes me happy.
My misdrevous was very stubborn at first and when I first caught her, she always had negative reactions towards me ):
Generally I don't like my uglier pokemon following me (like my victreebell,hypno, haunter or my graveler). But sometimes I let them follow me anyway so I give them equal oppurtunity.