The best replacement for simulator is emulator.

The best alternatives to simulator are rated as following:
★★★★★  emulator
★★★  x plane
★★★  realflight
★★★  trainz
★★  stimulator
★★  x-plane
★★  training device
★  agricultural simulator
★  farming simulator
★  trainz driver
★  xplane
★  virtual skipper
★  msts
★  simulation
  railworks
  microsoft flight simulator
  real flight
  virtual sailor
  launch monitors
  optishot
  drum simulator

Your alternative for simulator is not listed? Suggest!
Speaking about simulator, one probably shouldn't forget about google earth.

Other search terms related to simulator and their ratings are:
★★★★★ google earth
★★★ dx6i
cockpit
You have in mind a companion for simulator and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of simulator in all years. Click on graph for more.
simulator
emulator
x plane