The best replacement for webex is gotomeeting.

The best alternatives to webex are rated as following:
★★★★★  gotomeeting
★★★  skype
★★★  live meeting
★★★  adobe connect
★★★  dimdim
★★  webinar
★★  lync
★  netmeeting
★  citrix
★  jabber
★  intercall
★  google hangout
★  fuze
★  gotowebinar
★  logmein
★  gotomeeting which is better
★  zoom
  teamviewer
  join me
  at&t connect
  gotomypc
  breeze
  joinme
  anymeeting
  go to meeting
  microsoft lync
  elluminate
  join.me
  meeting place
  go to my pc
  gotomeeting pricing
  readytalk
  livemeeting
  video conferencing

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

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



Google Trends

Scale is based on the average worldwide traffic of webex in all years. Click on graph for more.
webex
gotomeeting
skype