The Imaam of Yemen, Muqbil ibn Haadi al-Waadi’i, said about Al-Albaani, may Allaah have mercy on them both, “He has no peer in this era. And it should be known that Shaikh Naasirud-Deen al-Albaani, may Allaah the Most High protect him, has knowledge/learning [from what he has had access to] which no one else does, and reference works became available to him which no-one else had. Many a reference is not available to us, so we have to quote it from the books of Shaikh Naasirud-Deen al-Albaani, referencing it back to him. So may Allaah reward him well on behalf of [what he has done for] Islaam.”
Ijaabatus-Saa‘il ’alaa Ahammil-Masaa‘il, p. 567.