(I'm not making this a regular thing, don't worry).
I used to say sitting room, but like settee, at some point I switched over to living room. I'm a Londoner, but had a Midlands mum.
Following on from the other post, I think if you say settee, you probably say sitting room. If you say sofa, you probably say living room or sitting room . Lounge definitely goes with couch.
Which term do you use, what region are you in/from? I'm not counting front room, because that's a separate thing imo. The front room is the good room, or "the parlour" if you're posh.
Grew up in the north-west, in a two-up, two-down and it was always the front room. When I was little it was synonymous with living room for me. I only realised it was not the same thing when my gran got annoyed with me for calling her living room the front room (she lived in a bungalow and the living room was at the back of the house). Nowadays still call it the front room back home, even though we moved house when I was 10 and it's no longer technically at the front. But anywhere else I'd say living room. And it's always been a sofa.