All I would have for you would be Sungkyunkwan Scandal, it's not very similar just because it's more on the comedic/romance side of historical dramas.
Arang and the Magistrate is another good one but it's also based in more of a supernatural time rather then a realistic time.
Iljimae is one of my favorite historicals(I watched it after TPM cause I needed something similar) but the romance aspect on it is almost non existent, just more of a crush, but it's a great drama.