I'm surprised by all the love for Skype I see here. Yes, it's useful, but that's just market share: if I want to talk to everyone else, I have to have it and (grr) make it work. But I'd hardly call it worthy of an award. Development on Linux is dormant. Bugs on Linux go unfixed for, literally, years. It only installs and works reasonably well on a small subset of distros. Not only the client is proprietary, the protocol is secret too, so you can't use an open source alternative to communicate with Skype users. And need I mention the new owners?
Skype fills a current vacuum. But like all vacuums, it sucks.