The Rabbi Blumenkrantz Pesach book – year after year – has been looked forward to by my family every time it comes out. The wealth of detailed information leaves nothing about Pesach to the imagination.
A Judaica store owner in New York told me that (even taking into account chumashim and sidurim)it is the most widely sold Jewish book in the world because so many people buy new ones every Pesach.
I don’t know if this is a fact, but it certainly deserves to have that title.