Notdumb

Sea foam
Rental onii chan
Nageku shinigami
World's end garden
Go to the manga directory and select one shot and tragedy (or whatever you like) and then filter it to popular. All the good ones come)

if you're looking for something warm and fluffy, I love this one:

http://www.mangago.me/read-manga/futari_hyakkei_kaze_no_owari_haru_no_hajimari/

Thank you ヾ(☆▽☆)

Honey lemon soda !! It’s a cliche but so cute

Sei chan, your love is too much ! It’s a very cute manga, It’s straight too.

Positively Yours
I Found Somebody to Love
Dubious Moon
Bring the Love
Christmas Miracles
The Lady's Butler
An Inescapable Love

Here some straight romance webtoons
http://www.mangago.me/home/mangalist/685444/?filter=&page=1
(completed ones)

Thank you very much everyone (=・ω・=)