These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Critical Dissonance: His first Duets album was widely panned on release as cynical, artistically negligible cash-in product. It then turned out to be the biggest-selling album of his career by a considerable margin.
Doubles as a Tear Jerker is the song "My Way". As he contemplates his life Frank admits that while he's made plenty of mistakes he's still proud of it, claiming that he lived it his way and no one else's.
Magnum Opus Dissonance: "My Way" is Sinatra's most famous song, yet he didn't write it himself (Claude François' "Comme d' Habitude" was the originator) and he didn't like it that much himself. Many Sinatra would likely argue that there are better Sinatra songs around, yet nobody denies that it sums up pretty much everything that makes the singer great.
Newer Than They Think: "My Way" and "New York, New York", the two songs most associated with him, were not recorded until well after his peak of popularity (from the late 1940s to the early 1960s). The latter is especially notable, as it was only released in 1980, but became iconic almost immediately.