Central fireplaces in long rooms are a challenge for decorating: If you make the fireplace a focal point, the two spaces on the end aren't really big enough to be useful; two seating area and you feel like you aren't using the fireplace to its best advantage; and three seating areas like you have feels a bit cramped. Personally, I would probably take it down to two seating areas and pull the two big chair into the living area with the sofa. If you stick with the three areas, I'd probably turn the chairs to face the fireplace. Your space reads "lodge" to me with all the wood. Lodge decorating schemes have a vernacular all their own, so something that would look dated in another house looks perfectly fine here. Your dining room lighting in a suburban tract home would look like a holdover from a misguided foray into faux Tuscan; in this setting they look like, "Oh, see how they chose chandeliers that kind of look like twigs to reinforce the rustic look." A lot of your furnishings look like they could be antiques (whether they are or not). It comes off as a conscious choice to embrace old-fashioned decor. That isn't the same as dated, which looks like it happened accidentally just because you haven't changed anything in 30 years. (Even if the latter is true, it doesn't look that way0. The road from lodge to coastal is long and expensive, and would involve changing the fundamental character of the house. IMO, it's never a good idea to fight the fundamental character of the house. Once you've decided on your layout, I'd start with rugs for the sofa group and the dining room. If you go with three areas, I might use rugs for the areas on the end and forego the rug in the center area. You can use the rugs to lighten up the space and obscure some of the wood.

In fireplace area, either a setup like this, with four chairs and center cocktail table or ottoman. Or I would put a three seater sofa on the one available window/door-free wall, the wall that has entry passage to bed and bath - and float the tv.

Build in/put in proper shelving/cases on both sides. Re-arrange your couches so they aren't invading the alcove area. That pretty little cabinet and table need to live elsewhere. Consider wall mounting your TV above where it is now, with it's equipment on the new proper shelving in that alcove.

The first thing would be furniture placement in the room. Without furniture placement, you cannot decide where to put the tv. Right now to me the best place would be the lower right side of the fireplace, but honestly you need to place furniture in the room to make that decision. What size tv will you be working with. Are you buying a new tv? Are you using furniture you already have? will you be buying a sectional? sofa and chairs? what furniture best fits this room needs to be decided. So many questions :-) Post all dimensions, walls, windows, doorways. If need be draw it out on paper and post a picture.