Now a days it is difficult to compare singers of same genre with nearly same voice quality due to far and few classical based songs but Shreya is all set to replace Alka. Other than Bollywood Shreya is a big hit in South Indian music and won Filmfare 2006 award for Munbe Wa.
Alka Yagnik is one of those who thinks Lata ji is swara personified and the best. She has enormous training under her mother and other gurus. She has demonstrated singing of various genre under several composers starting from LP, RDB to A R Rehman. Oldies like me will go for her.
So who is singer of your choice, please mention and give reason.