I have an unopened bottle of Seagrams from 1946, and a bottle of Old Forester from 1953, where time + the VERY heavy glass stopper cracked the plastic seal and broke the cork. Both belonged to my better half's grandfather
I once tasted some regular Cuervo gold my buddy brought to a cabin weekend. He was going to make margaritas (with HFCS mix) and I nabbed a pour to sip on. It was one of the best tequilas I've ever tasted. I couldn't believe it was Cuervo, and then he told me that it was a bottle his Dad brought back from Mexico in the 80's. Apparently that stuff was really good back in the day.