Since Arijit also passed the peak now so he is added to the list too , whom peak you really enjoyed with the choice of songs
My choice
1) Sonu Nigam : The Variety he has given to film industry is unparallel
he has given a sufi Satrange Re to passionate Yeh Dil Dewana basically Sonu Nigam was instrumental in bringing Passion/Aggression with westernised style in bollywood music my Top 5 Songs
In Lamhoon Me Daman Main
https://www.youtube.com/watch?v=ve4IQMlTMuY
Tanhaye
https://www.youtube.com/watch?v=ZkwaiIGoyT4
Sun Zara
https://www.youtube.com/watch?v=FUHB9uO6mgs
Bawri Piya Ki
https://www.youtube.com/watch?v=6Pq7ZK5FfzQ
Apna Mujhe Tu Laga
https://www.youtube.com/watch?v=KIzCpTA2p5Y
Aisa Dewana Huwa Hai Yeh Dil
https://www.youtube.com/watch?v=X4TyG9grBSw
2) Udit Narayan :
Although Udit Narayan career is mostly build on foundation of romantic songs but it still sounds fresh
Top 5 Songs
Mujhe Neend Na Aye
https://www.youtube.com/watch?v=rrZcR4GzWq8
Silsilay Mulaqaton Ke
https://www.youtube.com/watch?v=LFZynLIoFWQ
Jo Bhi Kasme Khayein
https://www.youtube.com/watch?v=ZVG5u3_o93U
Hume Tumse Huwa Hai Pyar
https://www.youtube.com/watch?v=siw7-MTgE4s
Hum Tumko Nigahon Main
5