The best replacement for cement board is green board.

The best alternatives to cement board are rated as following:
★★★★★  green board
★★★★  drywall
★★★★  hardibacker
★★★  vinyl siding
★★  ditra
★★  plywood
★★  wonderboard
★★  backer board
★  schluter
★  wood siding
★  gypsum board
★  green drywall
★  kerdi
★  waterproof drywall
★  tile backer
★  stucco
  sheetrock
  fiberboard
  densshield
  backerboard
  cedar siding
  asbestos
  blue board
  hardie board
  hardibacker board
  hardie backer board
  mud
  metal lath
  durarock
  greenboard
  green sheetrock
  wire mesh
  hardiebacker
  durock

Your alternative for cement board is not listed? Suggest!
Speaking about cement board, one probably shouldn't forget about tile.

Other search terms related to cement board and their ratings are:
★★★★★ tile
You have in mind a companion for cement board and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of cement board in all years. Click on graph for more.
cement board
green board
drywall