Dragon Naturally Speaking 8.0 is the best in world of voice recognition . But yes its costly . Its around 17K . But then you get Dragon Mice and Headset with it, a very high quality . You Get 1 year upgrade free and a lifetime support warranty.
Plus heavy discount from Dragon inc for lifetime .
It Accurately recognises the voice input in Indian accent with minimum amount of tranining . Lotsa custom options . Various modes for Lawyers , Medical ( Transcription ) , and other profession .
Minimum sys requirements 1ghz , 256Mb ram ( The more Ram the better in this case ) and 800Mb free space.
Remember to back up ur speech files every now and then and enjoy .