Of all the sacrifices mentioned in the Vedic literatures, the performance of sankirtana-yajna is the best. Even the performance of one hundred asvamedha sacrifices cannot compare to the sacrifice of sankirtana. According to the author of Sri Caitanya-caritamrta, if one compares sankirtana yajna to other yajnas, he is a pasandi, an infidel, and is liable to be punished by Yamaraja. There are many Mayavadis who think that the performance of sankirtana-yajna is a pious activity similar to the performance of the asvamedha-yajna and other such pious functions, but this is a nama-aparadha. Chanting of the holy name of Narayana and chanting of other names are never equal, despite what Mayavadis think.
From Srila Prabhupada's purport to SB 5.19.24