You will need a lamp for reading so a table with a good reading lamp , I would do a bookshelf where you have the chair now, no shelves above your head. As for an actual chair my advice always go shopping and sitting, no one can tell you what is comfortable for you.

if you need book storage, make the slim area where you have the tiny table into shelves.

Find a great comfy and a large framed art piece on the wall. A lap on the Rad cover next to the chair.

You can also figure for a corner shelving unit for book storage.

Also second on Patricia's suggestion for furniture selection, you will need to personally go out and test out what is comfortable for you.

Agree with all suggestions so far. AI needs to give you a footstool, lamp, table & afghan / throw to make the reading nook inviting. And, no shelves over our heads!

Consider functionality, lighting, comfort, and accessories. Maybe search on line for inspiration and it will really help with an overall concept. Fyi: I searched “small reading corner in living room” on Pinterest. The size/style of chair will now be easier to narrow down, consider an ottoman and accessorize the radiator. It’s important it tie into the room and can be done by just duplicating cushions and art in the seating area.

In this niche, consider shelving for your books.

Given the size of the space, I'd prioritize comfort over a statement chair. A chair you actually want to spend an hour reading in will always be the right choice. a small round table, a floor lamp, and maybe a narrow bookshelf would create a cozy reading nook without crowding the room.

Very nice ideas! Thank you!

Since you have a window seat (presumably over a raditator of some type) I think an additional chair would be overkill in that corner.

Thank you Norwood Architects, I agree however, unfortunately the radiator doesn't provide the "best" seating, in a pinch company can sit but not a comfortable situation. So trying to work with that.

A cozy reading corner sounds wonderful. Furnish it with a comfortable chair/ottoman or settee, side table or use the radiator cover, floor lamp, plant, books, art or etc.

Another inspiration photo for consideration. I like the dark walls and the scale of the chair and side table. The low cabinet reminds me of your radiator cover/window seat.

If you want to turn that radiator cover into a ledge, add a stone slab on top so you can put plants or a drink on it.