The best replacement for free weights is machines.

The best alternatives to free weights are rated as following:
★★★★★  machines
★★★  bowflex
★★  machine weights
★★  weight machines
★★  resistance bands
★  bodyweight
★  nautilus
★  bands
★  cables
★  machine
★  resistance machines
★  home gym
★  resistance
★  kettlebells
★  barbell
★  smith machine
★  machines pros and cons
★  machines bodybuilding
★  bench press
  total gym
  machines better
  calisthenics
  resistance training
  p90x
  exercise machines
  multi gym
  home gyms
  machine training
  circuit training
  machines fitness
  machine weight lifting
  barbells
  cable weights
  pulleys
  leverage machines
  body weight exercises
  machines training
  nautilus machines

Your alternative for free weights is not listed? Suggest!
Speaking about free weights, one probably shouldn't forget about resistance bands.

Other search terms related to free weights and their ratings are:
★★★★★ resistance bands
★★ squats
★★ soloflex
You have in mind a companion for free weights and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of free weights in all years. Click on graph for more.
free weights
machines
bowflex