Hopefully this isn't a single store deal, but my local Sainsburys (New Eltham) has 2 sets of DVD deals on at the moment.
There is an individual cardboard display stand away from the main DVD part (which is tiny in this store) with a stack load of different DVD's at reasonable prices. The only ones I was interested in were Borat at £2.99 and Walk the Line at £3.99, but there were quite a few more.
The other deal was at the checkouts where they have a selection (3 or 4) for fathers day. Again the only ones I paid attention too were Hancock at £4.99 and Flags of our Fathers & Letters from Iwo Jima (2 discs) at £4.99.
None of these prices are world beating (similar to what you can find on play or HMV.com) but helpful if you have a sainsburys near you?