I bought Hangover & Terminator Salvation so £10 each which seems to beat what I can find online.
Cant remember all on the deal but they were stand out along with
Harry Potter Half Blood Prince
Can't remember the rest but worth a glance if you are instore.
BY THE WAY......... The multibuy didnt immediately discount so if you do go for this then please check your receipt. I had to go get £4 refund from customer services.