For me Bleach
Canon Anime ships that you can't help but hate
Tomoya Okazaki x Nagisa Furukawa. Their relationship ended unrealistically. On the other hand, Tomoya Okazaki x Tomoyo Sakagami had better development in just one special chapter. I would have preferred to see a relationship with that ship, Tomoya x Tomoyo, it had potential for more but it's not cannon
Sasuke x Sakura
This is my least favorite one in Naruto
Also Naruto and Hinata xD
xD not that bad though, Ino x Sai, Choji x I-forgot-her-name-because-she-didn't-get-any-screen-time, Kiba x Cat girl, etc are all bad
For me there's a lot but most severely, everything in Naruto plus RenjixRukia.