Gakkou no Kaidan is a very hilarious anime. I had the pleasure of watching it dubbed and the comedy is in it is excellent, for me it is the best part, and what made this anime such a pleasure to watch. It is full of pop culture references and one liners, making nods to every thing from politics to celebrities.
As far as story goes, it doesn't change past, the kids encounter a ghost, and fight it off, but even with its static story, it remains entertaining and never becomes dull.
The character development also remains static, none of the characters really venture past the stereotypes that were created for them, however they are still compelling nonetheless.
I recommend it to anyone who enjoys black comedy mixed with supernatural and mild horror.