19 Av - R' Yaakov ben R' Machir Culi, author of Me'am Loez (1732) Here is an article on him, by R' Aryeh Kaplan.
19 Av - R' Naftali of Nemerov (1860) One of the closest talmidim of Reb Nachman of Breslov and one of the two witnesses to the promise about reciting Tikun HaKlali at R' Nachman's kever.
19 Av - R' Shimon Sholom ben R' Menachem Kalisch of Amshinov (1954)
19 Av - R' Menachem Nachum ben R' Yitzchok Friedman of Boyan (1936)
20 Av - R' Yehuda Zerachya Azulai (1870) was a great-grandson of the Chida
20 Av - R' Eliezer of Uzipoli (1865) ben R' Yehuda Tzvi of Stretin
20 Av - R' Levi Yitzchok ben R' Boruch Schneur Schneerson (1944) was father of the last Lubavitcher Rebbe, R' Menachem Mendel.
21 Av - R' Chaim ben R' Yosef Dov Ber Soloveitchik, Rosh Yeshiva of Volozhin and Rav of Brisk (1918)
21 Av - R' Ahron ben R' Yisachor Dov Rokeach, the Belzer Rebbe (1957) From the greatest tzadikim of his time. The numerous stories of his tzidkus and miracles are legendary. Many of the great tzadikim in Eretz Yisroel, from all segments, were very close to him. He lost his whole family to the Nazis y's. The fascinating story of his escape can be read in Rescuing the Rebbe of Belz.
21 Av - R' Alexander Sender of Komarna (1818) ben R' Yitzchok Issac was a talmid of the Chozeh of Lublin
21 Av - R' Dovid Hager of Zebultov (1848) ben R' Menachem Mendel of Kosov was a son-in-law of R' Moshe Leib of Sasov. He wrote Tzemach Dovid.
22 Av - R' Mordechai ben R' Hillel, the "Mordechai"HY"D (1298) killed during the Rindfleisch pogroms
22 Av - R' Meir Hagadol of Premishlan (1773) ben R' Yaakov "Tam" was one of the great talmidim of the Baal Shem Tov. The Nadvorna dynasty, with it's many offshoots descend from him. His grandson was the famous R' Meir'l of Premishlan
22 Av - R' Eliyahu Dushnitzer (1949), mashgiach of Lomza Yeshiva, Petach Tikva. The Chazon Ish is reported to have said that he was one of the 36 "hidden tzadikim". He was a talmid of the Chofetz Chaim and one of the ones chosen to get the dibbuk out of a woman, in the well know story told over by R' Elchonon Wasserman.