If you're having Downton Abbey withdrawals, may I suggest Robert Altman's Gosford Park? Written by Downton creator Julian Fellowes, it's a proto-Downton of sorts: lots of upstairs/downstairs with a dash of mystery. And the cast! Clive Owen, Emily Watson, Stephen Fry, Kristin Scott Thomas, Michael Gambon, Derek Jacobi, Kelly Macdonald, Helen Mirren, Ryan Phillippe...and Maggie Smith plays a witty countess.
Watch it on Netflix Instant, at Amazon, or on iTunes.