The best replacement for halo 4 is halo reach.

The best alternatives to halo 4 are rated as following:
★★★★★  halo reach
★★★★★  black ops 2
★★★★  halo 3
★★★  battlefield 4
★★  call of duty ghosts
★  killzone 3
★  halo reach graphics
★  bo2
★  crysis 3
★  gta 5
★  assassins creed 3
★  call of duty black ops 2
★  borderlands 2
★  cod ghosts
★  mass effect 3
★  far cry 3
★  cod black ops 2
★  uncharted 3
★  reach
★  mw3
★  halo 3 graphics
  bioshock infinite
  call of duty black ops
  gears of war 3
  modern warfare 3
  killzone shadow fall
  black ops 2 preorders
  black ops 2 sales
  call of duty: black ops 2
  last of us
  limited edition
  black ops

Your alternative for halo 4 is not listed? Suggest!
Speaking about halo 4, one probably shouldn't forget about smartglass.

Other search terms related to halo 4 and their ratings are:
★★★★★ smartglass
★★★★★ master chief
★ 4gb xbox
You have in mind a companion for halo 4 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of halo 4 in all years. Click on graph for more.
halo 4
halo reach
black ops 2