A photo would help. But honestly, a corner fireplace can be very cozy -- just build a collection of seating around it -- diagonal couch, chairs on either side, if space allows, or couch on one wall and a couple of chairs. Or you can semi-ignore it if you need to center your couch on, say, a TV. Depends on a lot of other factors -- e.g., is you TV in this room or elsewhere? Are you setting up a dining area at the opposite end of the room? Photos and/or diagrams will get you better advice.

Great input from acm. Your fireplace is the architectural focal point of the room. All seating revolves around it.