Basically anything from CLAMP, lol.
Truth be told, they like yaoi (even draw doujinshis) and there are always BL vibes.
I strongly recommend RG Veda and Wish. The side couple from CardCaptor Sakura is definitely cute too (and the stories are awesome).
Owari no Seraph (Seraph of the end) has BL vibes going on. And there's Evangelion too (and there is even a BL love confession and I can't handle this couple!!!).
This one: http://www.mangago.zone/read-manga/neon_genesis_evangelion/
But's not complete. There is an anime, but it's very different from the manga.
I'd like some plot heavy shounen ai or bromance. If bromance I'd like it to be pretty strong on the bl vibes, I've read part of loveless, and got sidetracked so that's one I'm aware of..silver diamond and the other by that author I've read. That's what I I have in mind, long, fantasy, adventure. Switch I've read, love it. Komatta toki ni wa hoshi, I read and it's my favorite Manga ever. Something like that too. I want long bromance or full on shounen ai. The lovier the better. Thank you