[Zircom]

They used to have a separate star button in addition to the like button that was exactly that, but they took it out years ago. It would also add the song to a separate list in your library called "starred songs".

When they axed the feature, all the started songs got automatically added to a new playlist called "Star" that I still use today as a workaround, I just add new songs I enjoyed to it to keep track of them, and just throw it on shuffle when I'm not in the mood for anything specific.