Speakers that sound great in terrible rooms

The main problem is not given by the environment, but by the incorrect synergy of the components inserted between them, and many times the incorrect electrical phase.
By solving these problems, you can really feel the physical limits of your room.
Obviously, in a small room, you can not insert speakers that "need air around", as they would be suffocated.In addition, with a DSP software or an audio calibration process software like Dirac for example, you can intervene on the frequency response by fixing the problems.
But it is something that I prefer to avoid, as the end result will always be a compromise.

I think the most difficult problem do address is bass, and a DSP EQ in the bass region is a great solution. My room is bad for bass from 40hz downwards and I solved this with the Parading Persona 9H...I have a great sound now in my terrible room.

I would agree with what some others have said regarding near field listening, avoiding reflections, and narrow dispersion speakers.  As a starting point you also want your seating position in a place where you have the most even bass response - play the room as they say.

Another vote for Larsen speakers. I have a room in which I have little flexibility in speaker and listening position. I've tried a number of speakers in that room over several decades and have never been satisfied. In the last year I installed Larsen 6.2 speakers. After all these years, I'm happy with the sound quality. I enjoy this system as much and in some ways more than other rooms where I have complete flexibility with the speaker and listening position. Others have also been impressed. When I play program material with low bass content, it sounds like I've added subwoofers.

Surprised that anyone that sensitive about not changing their room to improve sound would choose that room to set up a system in the first place.  Is there no other room in the house that would have better acoustics?

Sometimes performance of the room can be improved by just drawing the curtains - is that too much meddling in the aesthetics?

If putting the system in the best room in the house (from a sound point of view) or doing anything at all to eliminate glaring sonic issues are not acceptable, I'd say that the best speakers for that person would be a pair of really, really good headphones.