Sometimes I like a song, but when I karaoke it I still like it but realise it's actually not that hard to at least give it a shot [example: Black Sabbath/Ozzy, etc]. Other times I try and am blown away at how hard they are, however simple they superficially might sound [example: Steve Winwood, Cream, A-ha, etc]. Karaoke is not only fun, I find it a valuable channel to really understanding a song and it's composition.
An extension of this is cover versions of songs. Sometimes the cover teaches you more than the original did, and so they compliment each other. Here's one I came across today, of an old favourite of mine (on maaany years). My God the cover is loyal and accurate, but having the rare chance of seeing the finger-work behind it just makes me respect the original musician[s] more. Quite something.
https://www.youtube.com/watch?v=PRDhpC0R2ok
FOCUS - Hocus Pocus Cover