The best replacement for iphone 5s is galaxy s4.

The best alternatives to iphone 5s are rated as following:
★★★★★  galaxy s4
★★★★  5c
★★★  galaxy s5
★★★  note 3
★★★  htc one
★★  nexus 5
★★  galaxy note 3
★★  iphone 5
★★  4s
★★  lg g2
★★  iphone 5c
★★  samsung galaxy s5
★★  iphone 6
★  samsung galaxy s4
★  samsung note 3
★  droid maxx
★  moto x
★  samsung galaxy note 3
★  wait for iphone 6
★  android
★  samsung s4
★  s4
  htc one m8
  iphone 4s
  samsung s5
  6 in 2013
  samsung galaxy 4
  samsung galaxy s3
  samsung galaxy
  5c review
  iphone 5c 2013
  blackberry z30
  galaxy 4
  galaxy s4 specs

Your alternative for iphone 5s is not listed? Suggest!
Speaking about iphone 5s, one probably shouldn't forget about sprint.

Other search terms related to iphone 5s and their ratings are:

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★★★★ contract at&t
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★★★ metro pcs
You have in mind a companion for iphone 5s and it is not yet here? Propose!

Google Trends

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