Not sure what genre you're looking for. ^^
Manga: http://www.mangago.me/read-manga/horimiya/
http://www.mangago.me/read-manga/kodomo_no_omocha/
http://www.mangago.me/read-manga/kamisama_hajimemashita/ (Fantasy)
http://www.mangago.me/read-manga/sand_chronicles/
Yaoi: http://www.mangago.me/read-manga/love_mode/
http://www.mangago.me/read-manga/yatteraneeze/
http://www.mangago.me/read-manga/haru_wo_daite_ita/
http://www.mangago.me/read-manga/saa_koi_ni_ochitamae/
http://www.mangago.me/read-manga/tokimeki_no_seito_kaishitsu/
http://www.mangago.me/read-manga/bukiyou_na_silent/
http://www.mangago.me/read-manga/koi_wa_itsumo_arashi_no_youni/
http://www.mangago.me/read-manga/hey_class_president/
http://www.mangago.me/read-manga/fortune_fortune/
Do you have any recommendations of sweet, long mangas with nice plots and good characters?
Thanks so much in advance!!