Eastenders first declined for me in mid 2010, although it picked up in late 2010 to mid 2011 which imo was a good period. I know I'm in the minority when I say that. but I ADORED Glenda
and the baby swap storyline was not so bad. Summer 2011 it went downhill again though with the Eddie Moon rubbish and from then to autumn 2013 is probably the worst state it's ever been in. It's starting to pick up recently.
People always say 2006 was a bad year but it was a damn sight better than anything 2010 onwards. Grant's return, Stacey and Max beginning their affair, Get Johnny Week, the Down's syndrome storyline, the introduction of so many good characters etc. Killing off Pauline was stupid but it was still interesting and gripping