Very tough question. For me in the running:
1976 La Tache Monopole; 1959 Chateau Latour; 2010 Cune Imperial Gran Reserva Rioja; 2013 Chassagne-Montrachet, Les Embrazees 1er Cru from Vincent Morey; Gosset Grand Millesime Brut 2006. Trying the 2009 Dom Perignon at the winery was pretty cool as was tasting several at Guy Charbaut.
Most interesting wine was a 2000 L'Apparita, Castello in Ama (Toscana). Never had anything like it. It was in a blind tasting and I had absolutely no idea what it was. If you get a chance, seek it out. You've never had a merlot wine like this, trust me.
But, I think the winner is: 2003 Pesquera Janus Gran Reserva - consumed at Akalare in San Sebastian, Spain at an unbelievable lunch. It was their last bottle of the 2003. Got a huge smile from the waiter when we ordered it.