What i liked- Nibbler winning 'dumbest pet', Leela talking to Nibbler and finding out the brains plan on making people stupid (oh.... stupider), and that every religion is wrong, Fry trying to reeducate the PE crew, Fry's way of getting rid of the brain, the references to books like Tom Sawyer and Moby Dick, amongst other things.
good episode. it has a great, somewhat complex plot and has some very funnyscenes. what more could you want out of an episode? final grade is going to be an A+