The best replacement for l4d2 is tips.

The best alternatives to l4d2 are rated as following:
★★★★★  tips
★★★  l4d
★★  killing floor
★★  bots
★★  l4d1
★★  guide
★★  tf2
★★  dead island
★  single player
★  l4d2 beta
★  map
★  offline
  mod
  mw2
  change team
  ac2
  cod mw2
  survival

Your alternative for l4d2 is not listed? Suggest!
Speaking about l4d2, one probably shouldn't forget about garena.

Other search terms related to l4d2 and their ratings are:
★★★★★ garena
You have in mind a companion for l4d2 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of l4d2 in all years. Click on graph for more.
l4d2
tips
l4d