The best replacement for kit kat is snickers.

The best alternatives to kit kat are rated as following:
★★★★★  snickers
★★★★  twix
★★  reeses
★  jelly bean
★  nestle kit kat
★  reese's
  mars bar
  kitkat
  time out
  key lime pie

Your alternative for kit kat is not listed? Suggest!
Speaking about kit kat, one probably shouldn't forget about smarties cake.

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



Google Trends

Scale is based on the average worldwide traffic of kit kat in all years. Click on graph for more.
kit kat
snickers
twix