Couch. Mostly couch anyway.
My T works out of two offices. He's only at the office I go to once a week, and it's not really "his" office, I think he must swap space with the T who normally works there. So, it's not his choice.
The couch is ok, but the angle feels weird to me, compared to Ts chair. Like... if you were sitting around a table, you'd be on touching sides (with a corner between you). So, I end up having to sit at an odd angle on the couch to face T, which means I'm not really super comfy and there's no support for my back.

But it's ok.
In his office (I've only been there once, but going back this week), he has like four big big chairs. He gets one. All I remember was that they seemed huge. And no windows! And he doesn't sit in front of the door, like he does in the temp office... so I imagine my quick escapes going a bit faster!