It's not unusual for a great pop song to be covered by more than one artist. As recently as the '50s and early '60s it was more the rule than the exception that a publisher would make every effort to get a number of artists to do versions of a new tune with hit potential, then let the race to the charts begin.
The entries on this list represent instances where a song managed to have hit versions recorded by separate artists in more than one decade. If a hit song was re-released by the same artist in a subsequent decade and once again charted, that is another matter and may be the subject of yet another list some other day.
These are by no means the only examples of this occurring. Some on the list are obvious, and some not so, but hopefully all are interesting instances. Feel free to comment with other examples that fit the criteria.