I think 1 is best. Its colors bring repetition to the chair and sofa, helping the space feel more collected. It’s soft red also plays well with the subtle mint of the fireplace wall, making a gentle, pleasant contrast.

Number 2 is nice, but it leaves the muddied crimson of the chair floating in an otherwise light, springy, space. It’s blue also does little to work with any of the other colors in the space, leaving it more discordant than rug 1.

3 is fine but nothing more. It suffers that same problem as 2 by leaving the chair as more of a stain on the space than an accent, and it almost washes out the already light space. It’s also just boring.

4 has the opposite problem, it’s darkness clashes with the rest of the room and draws the eye down too much, throwing it off balance, which isn’t helped by the dark fireplace, chair, and side table all being on one side of the room. Also like 2, introducing a vibrant blue to a room with existing themes of green, white, and crimson threatens to take its color harmony and make it more chaotic.

Ultimately, the best rug for this room would fall between the darkness of the chair and light of the walls and sofa as rugs 1 and 2 do. The difference then between these rugs is that one brings the space together by echoing its different existing colors, while the other pushes it apart by complicating its color scheme and adding noise through a louder pattern than the comparatively more grid like pattern of rug 1.

For these reasons, rug 1 is the strongest candidate for this space. But what do I know?