Well, my bourbon bias is showing, but if you can't be biased in a poll, where can you be?
My favorite all-time 12yo would be/is the Wild Turkey 12yo, which was sold only outside the U.S. during the last few years of its existence. The Old Rip Van Winkle Old Time rye, also extinct, would run a close second.
Among extant bottlings, I think the W.L. Weller 12yo is both a great value -- under $20 for 750ml -- and a great bourbon.
From my Scotch 'holdings', I enjoy both the Highland Park Ornkney Islands and The Dalmore about equally.