I know this is an old show, but I just taped and recently watched all the Law and Order SVUs and CIs.  There are always reruns on.  I watched them over the last year.  There are so many it is impossible to watch them all in one month!   I love love love Goren!  However, I warn you.  When you do law and order marathons you become really paranoid! 

You already watch my other favs mad men, true blood, big love, sex and the city.  Since you have HBO on demand you could watch Rome.  I love Roman history, and BBC helped HBO make it.  It only lasted 2 seasons though, because it was too expensive to make and didn't generate enough interest.  For some reason, I have tried to get interested in Tudors, but I just can't get into it.

If you like history, I also recommend the John Adams miniseries done by HBO.

I watched the first 3 season of Greys Anatomy but it got really soapy and the doctors were always getting injured and becoming the patients and the accidents that happened got really unrealistic.