The "drunk deductions" stole my heart because as soon as Sherlock took a sip of alcohol I was waiting for it to happen and it didn't disappoint.
As I said I really enjoyed those parts of Sign of Three but Reichenbach had so many 'OH SHIT' moments it just blew me away. I think have a big central antagonist really helps for me; Adler, Moriarty & Magnussen are the highlights of the show for me.