IMO, “Goldfinger” is the *perfect *James Bond theme song, but “You Only Live Twice” is the most beautiful song to be a Bond theme.
Spectre’s song didn’t really grab me, but I loved the ones for the other three Daniel Craig films.
YOLT is my favorite of all the Bond themes. As you said, it’s a beautiful song, wistful, melancholy and a bit sad. I guess the tone of the song is appropriate…Aki’s death is one of the saddest Bond moments for me.
- “Goldfinger”
- “Live and Let Die”
- “Nobody Does it Better”
Best song in a James Bond movie that’s not its theme: “The Look of Love.”
Incredibly, Chris Cornell is the first person to pass away who sang a song featured in the opening credits of a James Bond film. RIP. 
Updated link: https://youtu.be/PRv6GvDRx9k
My favourite Bond songs are “Moonraker”, which doesn’t usually feature high on these lists but which I think is a beautiful song with uncharacteristically intimate lyrics for a Bond song, and “You Only Live Twice”, of which I prefer the glorious strings of the instrumental version to the familiar vocal version.
Fight on Kobe Docks from ‘You Only Live Twice’
Boat Chase (remastered) from ‘Live and Let Die’ (no link available)
Yes, Mr. Bleeker… I KNOW you “can’t just glue the wings back on…”
Ooh, if we’re going into the instrumentals: Koskov Escapes and Hercules Launch from my favorite film, The Living Daylights.