Leather couch, leather love seat or single wooden chair

There is nothing lonelier than an audiophile alone in a cave, so do everything you can for the two seat solution.

Your choice of speaker matters here. May I suggest Revel as an excellent speaker for couples, though they are not unique, but please give them a listen to hear an example of an excellent sounding speaker with a wide sweet spot. On the uber high end, Magico also exels here.

Also, good room acoustics widens the sweet spot, give GIK Acoustics a call.

Best,

E

There is a way to make a two seater work, at some loss to both listeners, but better than not. But this doesn't replace a single seat. Cross the axis of your speakers well in front of your head. The the person on the right, for example will be listening to the speaker on the left on axis but further away and the speaker on the right off axis which will be closer but where I presume the will be a loss due to off axis dispersion. 

Less than perfect for sure but it does work. Another solution would be to use omni speakers. The only loss here would be the loss of specificity in an otherwise huge soundstage.

Personally I gave my wife the family room and TV, I took the living room and stereo with a single central located Scandinavian stressless recliner. Man am I less stressed!@ :-) 

If your wife actually likes to listen, my advice would be to find a way to use the two-seater.

I use an Eames lounge chair in one room, and two "home theater" recliners in another.  The recliners are offset so one is in the sweet spot, and the other whatever.  Yeah, it's like that, here.

I vote for the 3 seater. This way you get the sweet spot for solo sessions, and get 1 or 2 companions for group sessions.

as awesome as a lone Herman Miller chair may be, it is a lonely thing. Perhaps 3 Herman Miller chairs!