At the moment we have several things such as Skype, Mumble, Appear and TeamSpeak wich are all very popular amongst gamers. And they all work fine, but the modernizing updates for the apps is just a shame.
Skype has for example had this "survey" for over 10 years now after every call asking what you thought of the quality of the call was. Still it haven't changed much after all this time.
Mumble also works fine, the only problem is the messy control panel and the horrible design that looks like it was made in the 90's.
I don't know too much about Appear, but i know it runs through the browser.
I haven't used teamspeak as much but i know for a fact that it's also got a pretty outdated interface with several limitations.