Recently I had a chance to test-drive ooVoo for video calls on a Windows PC. In the past I had been using Skype for all video call, but its state-of-the-art behavior makes me sick.
I already complained about inevitable forced updates which Skype doesn't allow to disable - they are downloaded in any case, and you are prompted with the update again and again... until you set no-access permissions for "?:\Users\xxx\AppData\Local\Temp\SkypeSetup.exe". I guess, MS will take care of this "exploit" in future versions, but basically I don't care - I'm using Skype 5.2, and is ready to drop it as soon as a decent alternative is found. And there are quite a few of them already on the free market...
The most promising is ooVoo (see the hint how to get its offline installer): video conferences, offline messages, video recording are the features you won't find in Skype for free.