This week, June 15th through June 21st, Best Buy is offering two Blu-ray movies for $25. Pick any two titles from the 29 offered and get both for $25.
And there is another deal than I think I missed earlier, it started on May 11th and runs through July 5th. Get two Blu-ray movies for $30. For this deal choose two titles from the 40 being offered, and get both for $30. Note that there is some title overlap between the two deals, so definitely check out the first, and less expensive, deal first.