I know that this was kicked around a while ago, but I just made my annual call to DTV to get my $150 off the NFL package. Got more than I bargained for. I talked to the customer retention department, just ask for them first thing. Told them that I was considering not only cancelling my NFL but going to Comcast altogether. They made the first offer, and I told them that I have Comcast in front of me and can get it for much cheaper.
They took off my HD charge for a year
They gave me movie channels for a month
They gave me the NFL package for free
5 minute call to save $400 this year, worth a shot