I will second the Dynaudio recommendation...the model Focus 140 is also excellent with piano.
I will also add several BBC type monitors such as the Harbeth Compact 7, Harbeth Monitor 30, Rogers LS 3/5A, and Spendor SA1.
I will also add several BBC type monitors such as the Harbeth Compact 7, Harbeth Monitor 30, Rogers LS 3/5A, and Spendor SA1.