Today I listened to a song that I was surprised to discover via YouTube: "Sugar Baby Love" by The Rubettes.
A few years ago I first heard the following version of the song as the theme song for "Sugar - A Little Snow Fairy" (released in 2003) and it was instantly one of my favorite anime theme songs (I listened to it as I wrote this post) and was enough to get me to buy the first DVD in the series (the entire series is excellent). At the time I didn't know that it was first recorded by The Rubettes or that there were other versions of the song (I also found two other versions of this song).
Which, on a whim today while surfing YouTube, led me to the discover of the original version recorded by The Rubettes which hit the charts in 1974 and is also an excellent song.