The best replacement for sofa is couch.

The best alternatives to sofa are rated as following:
★★★★★  couch
★★★★  sectional
★★★★  loveseat
★★  futon
★  couch difference
★  settee
★  fabric sofa
★  leather sofa
★  sager
★  chair
  fip
  sofa
  lilo
  coach
  t-sofa
  bed
  sofa bed
  leather
  recliner
  bonded leather sofa
  divan
  chair bed
  3 cushion sofa
  davenport
  sofa and loveseat
  fabric
  cloth sofa
  microfiber
  devan
  sleeper
  lane reclining sofa
  couches
  daybed

Your alternative for sofa is not listed? Suggest!
Speaking about sofa, one probably shouldn't forget about chaise.

Other search terms related to sofa and their ratings are:
★★★★★ chaise
★★★ chaise lounge
sleeper bed
You have in mind a companion for sofa and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of sofa in all years. Click on graph for more.
sofa
couch
sectional