Here are tts voices in different categories such as Ivona, Loquendo, Cepstral, Realspeak (Nuance), Vocalizer Expressive, ATT Natural, Neospeech. Click on any category you like and you will see voices to download
Elan Sayso, Telecom, Infovox2 and Infovox3
ATT Natural
Cepstral
Cereproc
Ivona
Loquendo 6 and Loquendo 7
Microsoft Azure
Neospeech
Realspeak
Vocalizer for Automotive and Vocalizer Expressive