Both, but for different reasons. Daffney's so bubbly (no pun intended) and full of personality, plus something about her makes her such a fun character. As for Casey, she definitely identifies with those who are "the girls next door" and is a relatable character, although she has the tendency to be quite the drama queen at times. Casey also comes across as more of the "boy crazy" type as opposed to Daffney (think Allstar and Stevie), in my opinion.