A nice large plant in a bright ceramic pot. I would put a smaller picture on the wall that's straight.

A round table with lamp and pictures hung on wall above.

These are great ideas but I should have added I have a 4 year old and a 16 month old so it would need to be somewhat kid-friendly. Adding artwork or photos is definitely the plan. It's just the floor space. I want it to be useable if possible.

Anymore suggestions?

a small bench or small oval table or coat rack

kid friendly pillows could be fun...or a fun beanbag chair. (see below) Or...depending on your budget, a built in bench (with storage and a cushion) that follows the curve could look nice with pillows to form a cozy seat and would be functional as well. Imagine that fun bear beanbag chair in your entryway! :)

Play with the curve with an offset gallery wall. The curve makes for a lot of visual interest and you can customize it with all the pictures you want!

The curved wall is so nice, you don't need to clutter the floor to fill the space. Just enjoy the architectural feature of it.

A small round table with lamp would work. It looks like you have enough room for a small chair on either side.