A coffee table grounds the room and pulls it together. It provides the central spot of the conversation area. Besides being visually appealing it serves a purpose; it provides your guests a place to rest their beverage or for you to place snacks. It can even provide great storage within the table or hidden inside.
A coffee table works even in a small area. A bench that is only 12" - 18" wide makes a great coffee table in a limited space or two cubes placed side by side also is a space saver.
If you have children and are worried about sharp corners, a large leather or upholsterd ottomans is the way to go.
In my opinion a living area without a coffee table is an incomplete room. It feels as though something is missing and there is!!