I was looking for something to make a voicemail greeting since my recorded voice is nasty. This one gave me a big wow:
AT&T Labs Text-to-Speech: Demo (http://www.research.att.com/~ttsweb/tts/demo.php)

Does anyone use a text to speech synthesizer that you like?

That's the one I've been playing with for years, since about 2002. It has come a long way.

I'm bummed that they only allow 30 words. It's the best sounding one I've ever heard!

Make multiple files and edit them together with Audacity (http://audacity.sourceforge.net/).

Hey, cool. I'll check it out. Here's a software app that uses the same engine voices... but one voice for $40 is a bit pricey in my book.:
Text to speech software with Natural Voices-- Free NaturalReader (http://www.naturalreaders.com/)