My sister do not like the sad episodes. She does not like sad stories. I however daps the tears of my cheeks and smiles while I have my heart broken over and over again by the best stories. The sad stories lends depth and meaning to the happy ones. Makes them mean something.
My favourite eleventh doctor episode is The Girl Who Waited because it has so much emotional impact. It is extremely sad and all of the charters has to make such big and harsh decisions.