Spongebob was my son's first cartoon. Thanks Grandma! But, I didn't specifically say no Spongebob so....
Other than being extremely annoying (that song gets in your head and never leaves) it isn't bad, especially compared to other stuff out there.
If you watch it you'll find:
1. Spongebob has an amazingly positive, cheerful, glass is always half full view on life. Refreshingly happy.
2. While they can be silly and stupid to each other, they always realize they care for each other at the end.
3. Spongebob himself gets very upset at anything mean or hurtful.
4. The "mean" characters usually get caught and reform themselves to an extent in the end. Lots of problem solving - just not obvious stuff.
5. The little violence there is is just so incredibly over the top that DS has always realized it is fake. We call it being silly.
You wanna talk evil? Let's talk Barney. That purple monster is not allowed in our house. Ever.