My favorite is easily Patch, for her adventurous nature and her ability to see that the Tales boys were not worth mooning over. (Hey Starlight and Sweetheart, you know what a good trait is in a boy? When he DOESN'T constantly try to make you feel like garbage. PCHOOO! MIND BLOWN!)
My least favorite of the girls is
Spoiler
Sweetheart. She reminds me of this fake-sweet girl I knew in grade school / middle school who would 'innocently' say things in a sickly-sweet voice that she knew would stir up drama. I do not trust Sweetheart at all. I also find her voice annoying.