The best replacement for guitar rig is amplitube.

The best alternatives to guitar rig are rated as following:
★★★★★  amplitube
★★★  pod farm
★★  pod
★★  revalver
★  amplitude
★  pod hd
★  axe fx
★  waves gtr
★  line 6
★  guitar pro
★  gearbox
★  th2
★  eleven rack
★  mainstage
★  eleven
  logic amp designer
  real amp
  amplitube 3
  toneport
  pod xt

Your alternative for guitar rig is not listed? Suggest!
Speaking about guitar rig, one probably shouldn't forget about reaper.

Other search terms related to guitar rig and their ratings are:
★★★★★ reaper
★★★★★ ableton
★★★ rocksmith cable
★★ m-audio fast track pro
★ fcb1010
★ foot controller
You have in mind a companion for guitar rig and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of guitar rig in all years. Click on graph for more.
guitar rig
amplitube
pod farm