We have hardwood floors in the living room, and a sofa that is positioned somewhat in the center of the room. Since there is no rug under it every time you sat on it, or espcially when Ferris flung himself on it - it would move.
I tried cutting small pieces of those rubbery rug underlayments - but the sofa still moved.
Finally, I put some duct tape on the sofa feet - no... not sticky side down, I simply stuck a piece of tape on each one.
The sofa hasn't move since.