Are you the renter, or the owner? Do you need to get more seating in the room, or what is your objective? May we see the other side of the space?

We are renting an would like to get an apartment sized couch in there yet not ignore the fireplace. We need more seating for little get togethers.

Budget minded chairs to flank the fireplace for extra guests... $85

Bench as coffee table that you can move around for larger gathering/seating...

What is the size of the dining room? Consider using a banquette instead of a sofa along one wall, moving the table here by the window and fire, and moving the sofa out into the dining room space. The tv can be under the beam / intersection so you can enjoy it from both rooms. A banquette like they sell at ballard designs can provide lots of extra seating when friends come - you can get a round crank up / crank down round table that can be both dining and coffee table if you don't currently own a table -
can you sketch all the public areas with dimensions / take a picture and post? I can help you more . look at this - you can get wipeable sunbrella and it will be functional for you nearly anywhere you move . . it is kind of nice to sit at a table with a laptop to watch tv and a banquette is cozy .
http://www.ballarddesigns.com/furniture/dining-kitchen/banquettes/?redirect=y