The various Audio Note speakers are quite good at delivering satisfying sound at relatively low volume levels, which is a big plus in an apartment. I would also suggest looking at ProAc speakers for the same reason. The old BBC monitors, such as the LS3/5a and the other similar models are good candidates too. Modern versions are still being made by the likes of Graham Speakers and Stirling Audio. Many of the DeVore models also sound pretty good at lower volume levels.
If you have the room to allow for the speakers being out in the room, dipole speakers are particularly good at concentrating the sound in the listening area and thereby reduce the volume leaking elsewhere. I found a dramatic difference in sound leaking to other rooms when I went from Martin Logan hybrid electrostatics to conventional dynamic speakers.