Anime series, OVA, specials and movies yaoi themed. Some I've seen, some are on my 'plan to watch' list.
slashable anime has some bl moments or hints of guy x guy moments. but nothing more than that. no kiss or anything. hugs or holding hands the most you can see. and it never implied that the 2 guys will be together or not. but you'll know that they have feelings for each other. and the romance is usually not the focus on the anime. it's usually shounen or shoujo. while yaoi/shounen ai anime is very obvious. kiss, hugs and even more than that will be shown.
MANGA: http://myanimelist.net/manga.php?genre[]=33
SOURCES:
http://en.wikipedia.org/wiki/Yaoi
http://www.watchanimemovie.com/sub-dub/category/yaoi
http://www.yaoiotaku.com/forums/media.php?do=category&cid=1
http://boysloveandslashableanime.wikia.com/wiki/Anime_List