Belong together: Izuocha
Rejected: Bakudeku
The enemies-to-lovers pairing of Katsuki Bakugo and Izuku Midoriya, to be honest, will never happen. They're enemies, plain and simple. Bakugo wants to become better than Midoriya and envies him because he is Allmight's successor.
Belong together: Kiribaku
Rejected: Kirimina
Mina Ashido and Eijiro Kirishima are kind of a cute couple, but they don't have all that many scenes together and their relationship isn't very romantic. They don't really have the interactions and buildup to become canon, either.
Belong together: Momojiro
Rejected: Todomomo
Yaoyorozu and Todoroki are kind of awkward around one another, don't have many scenes together and are just not that amazing in general. They work better as classmates or maybe even as friends, but they're not friends with the same people and don't really have similar personalities. I would defend this ship by saying that Todoroki kind of helped Momo regain her confidence when they fought Aizawa, but it was Midoriya who encouraged Todoroki to use his fire and not Momo. She doesn't really acknowledge him and he doesn't really acknowledge her.
Belong together: Tododeku
Rejected: M*neta and anyone.
M*noru M*neta is a horrible and perverted character who sees women as objects he can mess around with, without their consent. Everybody in the show has said he needs to learn. His behavior around Momo when he attached his grapes to her back was stupid and unacceptable, and the time when he looked through a hole in the wall into the girls locker room and commented on each of their bodies was a terrible thing to do. Basically the entire fandom hates him and he doesn't deserve a love interest (nor will he get one).
Belong together: Erasermic
Rejected: Kacchaco
Bakugo and Uraraka have no scenes together, barely acknowledge each other's existence and are friends with other people. They're totally different, and not in a compatible way. Uraraka clearly likes Midoriya anyway, and Kacchan basically hates Deku's entire friend group, which includes her. Ochaco would never like someone who always tries to be better than everyone, and her cute, happy personality would never match with his aggressive nature.