Firstl, the prank calls are hilarious, the arguments that happen are brilliant. "there is a pigeon in your bank-vault"- CLASSIC!
But more than simple funny prank phonecalls, the creator of the show has crafted a select core of characters which make repeat appearences throughout the series. George, the banker is hilarious. Terry Tibbs is my personal favorite- "Talk to me!"
On top of this, though, the icing on the cake comes from the visuals. a mixture of videos and slides, the accompany the calls perfectly and keep your maind enaged and entertained, and usually provide thier own hillarity input.
This is a top show, Id reccommend anyone to give it a go.