The best replacement for action replay is gameshark.

The best alternatives to action replay are rated as following:
★★★★★  gameshark
★★  codebreaker
★★  action replay max
★★  code breaker
★  an event
★  golmaal 3
★  codes
★  xploder
★  r4
  gameshark gba
  gts
  powersaves
  game genie

Your alternative for action replay is not listed? Suggest!
Speaking about action replay, one probably shouldn't forget about r4.

Other search terms related to action replay and their ratings are:
★★★★★ r4
★★★ pokemon black and white
★★★ pokemon x
★★ pokemon black
★★ pokemon white
★★ desmume
★ pokemon platinum
★ pokemon black 2
★ pokemon
★ pokemon white 2
★ pokemon diamond
action replay
ds
pokemon heart gold
codes
halo 2
You have in mind a companion for action replay and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of action replay in all years. Click on graph for more.
action replay
gameshark
codebreaker