The best replacement for google talk is skype.

The best alternatives to google talk are rated as following:
★★★★★  skype
★★★  google voice
★★  google chat
★★  yahoo messenger
★  aim
★  hangouts
★  gchat
★  gmail chat
★  chat
★  bbm
  lync
  facetime
  jabber
  viber
  voice
  hangout
  google hangout
  messenger

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

Other search terms related to google talk and their ratings are:
★★★★★ video
★★ google voice
★★ aim
★★ ichat
★★ trillian
★★ pidgin
★ gaim
jabber
miranda
You have in mind a companion for google talk and it is not yet here? Propose!



Google Trends

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