Based on a recommendation by my blogging buddy Ivan in "Thrilling Days Of Yesteryear" (find the link to the left), and since I've always been fascinated by the premise of the show, I picked up the two boxed sets for 'Checkmate'.
Best Of Season One
Best Of Season Two
The series starred Sebastian Cabot, Doug McClure, and Anthony George as the investigators at a San Francisco detective agency. Their original premise was to prevent crimes from even happening in the first place, but I think this was relaxed by the second season.
I've only seen one episode at the Paley Center, which starred James Whitmore, but I'm looking forward to seeing more....