The best replacement for bad is badly.

The best alternatives to bad are rated as following:
★★★★★  badly
★★★★  good
★★★  poor
★★  evil
★  worse
★  good cholesterol
★  feel badly
★  good list
★  thriller
  inherently good
  evil eminem
  good carbs
  good quotes
  ghostbusters
  good fat
  wire
  mad
  good esn
  weeds
  dexter
  to bad
  walking dead
  good food
  nice
  sons of anarchy
  i feel badly
  game of thrones
  bed
  house of cards
  good games
  right and wrong
  no credit cards
  good and evil
  badly grammar

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

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



Google Trends

Scale is based on the average worldwide traffic of bad in all years. Click on graph for more.
bad
badly
good