Yisan had a semi-tragic end. Semi-tragedy in sense that they do end up together and they loved and lived in the place, but like all royals in joseon era, the history of long life is not so good. Though for the most part, it still prettu sweet between the 2 leads.
But Yisan is one of the great Historical dramas. Coincidentally, all 3 (jewel in the palace, dong yi and yisan) are from the same team. My fave among the 3 is Dong Yi, mainly cause it had its cute moments between the leads while the other 2 mostly has very heavy storylines.