Castle is just plain fun. Their cases can actually be pretty interesting sometimes, but the true gem of this series is the interaction between the characters. The cast play off of each other flawlessly.
"The question is this: when you come right down to it, would you be willing to to break her out of prison? Because that, my boy, is true love." Martha to Castle; Castle TV show quotes; and then Beckett tells castle she'd get him out of there