1st REASON TO CHANT 'NITYANANDA':
BECAUSE GREAT ACHARYAS (spiritual preceptors) HAVE DONE IT IN THE PAST:
Caitanya Caritamrita, Adi 11.33:
navadvipe purusottama pandita mahasaya
nityananda-name yanra mahonmada haya
"Purusottama Pandita, a resident of Navadvipa, was the Krishna's eighth gopala, Stoka-Krsna for Vrindavan. He would become almost mad as soon as he chanted or heard the holy name 'Nityananda'."
Caitanya Caritamrita Adi 11.34:
nityananda-name haya parama unmadi
"Balarama dasa always fully tasted the nectar of love of Krsna. Upon chanting or hearing the name of 'Nityananda', he would become extremely maddened."
For more information about the great associates of Lord Nityananda, please check out this link: http://nitaai.com/nitaaive