I just came across this free credit score and report service, called BorrowWell.com. They appear to respect your privacy (other than running several privacy bug trackers on their website), and make their revenue through referrals like loans and credit cards. Note, BorrowWell only uses Equifax, so read on to make a TransUnion manual request as well.
I recommend at a minimum of an annual credit check, as this is how many people find out they've been victims of identify theft -- make sure all of the items listed in your report are credit items you've requested. By law, credit reporting agencies have to provide you with a free annual report, but charge you for an online account, so you can manually request your credit score if you don't trust borrowwell and don't want to pay Equifax/Transunion.
Once a year print of these documents: Equifax free report request form [PDF] and TransUnion free report request form [PDF]. Note that these two organizations are not synchronized, and in my experience you have issues reporting on one of them, or not the other, so make sure you're checking both!