Sad/heart breaking. I cried...
http://www.mangago.zone/read-manga/cover_up/
http://www.mangago.zone/read-manga/cocoon_of_the_heart/
http://www.mangago.zone/read-manga/december_rain/?av=1o
http://www.mangago.zone/read-manga/10_years_where_i_loved_you_the_most/
http://www.mangago.zone/read-manga/life_senjou_no_bokura/
http://www.mangago.zone/read-manga/hyperventilation/
http://www.mangago.zone/read-manga/utakata_no_uroko/
http://www.mangago.zone/read-manga/lifeless_man/
http://www.mangago.zone/read-manga/code/
http://www.mangago.zone/read-manga/kowagaranai_de_soba_ni_ite/
http://www.mangago.zone/read-manga/almost_paradise/
http://www.mangago.zone/read-manga/cosmic_boy/
http://www.mangago.zone/read-manga/trace_of_you/
http://www.mangago.zone/read-manga/kyou_mo_ashita_mo_asatte_mo/
http://www.mangago.zone/read-manga/hatsukoi_wa_gunjou_ni_tokeru/
http://www.mangago.zone/read-manga/see_you_later_mermaid/
http://www.mangago.zone/read-manga/nigatsu_no_eden/
http://www.mangago.zone/read-manga/hina_wa_mitsuiro_no_koi_ni_torawareru/
Last time i cried while reading a manga was lonely to organdy but it wasnt really because of the manga itself and more because i just felt like crying at the moment
Other than that i may had another but i dont remember
I do remember anime that made me cry, banana fish had me bowling like a baby for like half an hour at the last episode and natsume yuujinchou had me in tears at a spoiler moment

I recently read Love So Life and cried HARD at a certain scene. I don't think I've ever cried so much from a Manga. lol