The only Simpsons food I've seen around here are lollipops. And come to think of it, that wasn't here; I got them when I went to California. But I did see a commercial last week for Ritz Smores that apparently now have the Simpsons' faces on them.
A local brewery made Duff Beer a while ago. Was just normal beer in a fancy can. You could buy a carton of 30 for $30, but now the few remaining cans sell for about $50 each!