You can try LinguaScribe. Its voices don't sound like robots. It has got some great human-like voices. You can give it a try! I'm trying it for my videos. Changing the audio language and voice is fun and brings in more local audiences actually. Of course, there are various options but this one's worked well for me. So, suggesting you too.I have about 100 2-3 minutes instructional videos. Text is all ready but can't be bothered to read it all myself.
Is there any decent text to speech software or does it all sound like a robot still?