The best replacement for google voice is skype.

The best alternatives to google voice are rated as following:
★★★★★  skype
★★★  google talk
★★★  youmail
★★★  vonage
★★  siri
★★  talkatone
★★  line2
★  hangouts
★  ooma
★  magic jack
★  s voice
★  grasshopper
★  magicjack
★  yahoo voice
★  whatsapp
★  viber
  google voice lite
  verizon visual voicemail
  google phone
  3jam
  hangout
  talk
  rebtel
  skype international rates
  skype number
  ringcentral
  you mail

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

Other search terms related to google voice and their ratings are:
★★★★★ sprint
★★★★ hangouts
★★★ xmpp
★★★ tmobile
★★★ using minutes
★★★ obi
★★★ landline
★★ ooma
★★ voicemail
★★ ting
★★ google apps
★★ sip
★ extensions
★ google talk
★ virgin mobile
★ magicjack
★ talkatone
★ existing number
★ republic wireless
★ asterisk
★ sipgate
★ voip
gizmo
You have in mind a companion for google voice and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of google voice in all years. Click on graph for more.
google voice
skype
google talk