Super Lovers
http://www.mangago.me/home/mangalist/11763/
check out my incest list number 2-6, 9, 12-14, 31-33, 35, 41
If you look up the tag "incest" ( http://www.mangago.me/tag/incest/ ), 49 pages of possible manga come up, most of them yaoi. Then, if you click on the ones that look interesting and read the summaries, tags and comments, I'm sure you can eliminate the stories which don't appeal to you. If you find one you really like, take a look at the front page and who has included it on various lists. That way you will probably find someone whose shares tastes in manga that are fairly close to yours, and they will lead you to a bunch of stories you like in other genres. I recommend doing it this way because I have no idea if you like soft, fluffy incest, or hardcore and dark stuff, if you are into other kinks or just want plain vanilla plot-heavy stories.
I have a stepbrother and adopted brother list
http://www.mangago.me/home/mangalist/33429/
I'm looking for incest (preferably yaoi), and wanting it to also have a good plot. Like, it doesn't matter if they're actual brothers or not, I'm just a big fan of step siblings falling in love despite that their parents might think it's gross :'D