What do people use for Text-to-Voice?

I find that I often listen to long articles/blog posts using Apple's in built text-to-speech (when you highlight the text and right click while using Chrome or any Apple browser or text app, then hit speech).

Its still rather bad and I wondered if anyone has a better solution for more natural sounding text to speech whcih is easy to use, at my finger tips for when I want to listen to a long article while designing or playing a game..?