I think they're both good in their own ways. Casey's the smarter one, no doubt about it. She's a lot more down-to-earth and serious than Daffney, making her a good companion for the Snorks' many adventures. Daffney is kinda ditzy, but she's got a bright, cheery personality. She seems like she'd be more fun to hang out with than Casey.
If we're going purely by looks though, Daffney wins easily.
I guess I'll have to agree with you, Ryan. I tend to have found Daffney very funny. Her personality quite comical just by the way she's potrayed. That's probably why I'd pick Daffney. For so reason Casey potrayed sounds like those girls in the soap operas. (too dramatic and always serious in my opinion)
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.