Try Tokyo Ghoul.
I already read Tokyo Ghoul ^^
how about skip beat
tokyo crazy paradise or skip beat
How about these? : Adekan, Hakkenden, Durarara, Nurarihyon no Mago, D. Gray Man
For long series that is completed, Death Note, Kamisama no Iutori, and Binbougami ga!. For incomplete but still long, Shokugeki no Souma, Apocolypse no Toride, and Adekan. All of those do not have much romance. For BL, Kiraboshi Dial, Rutta to Kodama, Seven Days, Junketsu Drop, and anything by Yamamoto Kotetsuko. All of those were complete. For just regular boy and girl I recommend Koe No Katachi, Hibi Chouchou, Ao Haru Ride, and this may seem like a yuri manga (its straight), Usotsuki lily. Koe no Katachi is tragedy, so if u dont want to cry while on vacation dont read it.
Gaukuen Alice, Kamisama hajimemashita, the one, red river, bokura ga ita , junjou Romantica, sekaiichii Hatsukoi, crimson spell
Try bakuman, it's interesting and complete.
Tomorrow I'm going in vacation, I need some long (more than 15 chapters) manga
It can be anything ( not ecchi or harem) but something interesting. I'm okay with hetero romance but... It have to be awesome then !
I don't like too much horror but why not.
Thank you !!!