There's no competition, Honest .
She is like Bradman+Tendulkar+Lara+Laxman+Mark Waugh+Dravid+Gavaskar - ellAm avanga dhAn.

Sunidhi - asa boosa mAdhiri avangaLukku oru range limitation irukku; avanga range-la she is the queen but Shreya is not far behind as she has taken sensuous numbers and aced them, too. Ofcourse, pure item numbers-la, Shreya isnt the first name that comes to mind but who cares about those?

Sipla Rao, Rekha Bhardwaj etc - niche players; I cant remember Shreya doing much of their niche but then I havent been listening to much HFM in last two years.

ChinnammAyi, Mahathi, Manjari etc - no way near the Queen of Indian Film Music.