To think it's

[Pyjamaramadrama]

Living room not lounge
Breakfast-lunch-dinner not breakfast-dinner-tea
Pudding not dessert

How do you say it and which ones annoy you?

Ophelia. I have a chaise-longue. It's in my dining room, but I may rename that to supper room now

But strictly speaking, I think my chaise is a meridienne.

Breakfast Elevenses Luncheon High Tea Supper Nightcap

jessbow. Are you a hobbit?

Front room / living room (I say both)
Breakfast - lunch - dinner
Afters
Sofa

Front room (although it's at the back )
Breakfast, dinner, tea
Pudding

I just looked at the list on Wikipedia and I say a mix of both. I am definitely common though

living room
breakfast-lunch-dinner
afters
settee