Linear, corner, peninsula, with chaise longue, with meridienne, with Terminal library, with matching armchair, modular. Dare I say “who so on and so forth.” There are many variants, not to mention that each model is available in different sizes.
To choose the couch considering the size of the living room, consider what other furnishings include the environment, consider useful spaces for passage. Knowing these three factors you will be able to assess the maximum space you can allocate to the couch. Don’t forget to think about your habits and desires.
For a larger study I recommend reading this quick guide on choosing the right sofa.