Rarely has a farewell been so painful.

On April 5, Mad Men returns for its final seven episodes, and we are forced to accept that one of the most compelling dramas of the last decade is coming to an end.

As we say prepare to say goodbye to Sterling Cooper Draper Price and those surrounding the ad agency, Mashable asked the cast for one last look at how far the main characters have come and some of the episodes that defined them.

'Mad Men': Key character episodes

What have been your favorite episodes of Mad Men? Tell us in the comments, below.