Yuki Cross' earliest memory is of snow and blood - she was attacked by a vampire only to be rescued by another. Ten years later and Yuki has been adopted by the headmaster of the prestigious Cross Academy. This school is unique in that it consists of 2 classes - a Day Class and a Night Class. The Night Class is made up of vampires led by Yuki's rescuer all those years ago, Kaname Kuran. Together with Zero Kiryu, a childhood friend who despises everything to do with vampires since his family was murdered, Yuki must serve as a Guardian of the school to keep the two classes separated. Secrets lie beneath a peaceful exterior and not everything is as it seems, as Yuki learns the truth about Kaname, Zero and her own forgotten past.
These two manga are remarkably simliar in characters, style, story, drama and romance. Junketsu has less characters then Vampire Knight and has a lit bit more nudity (though nothing that would make it mature) but both are very similar.
Peronally, I believe that Vampire Knight pulls off the "serious vampire love interest" way better than Pureblood+Boyfriend. In fact, the latter seems to be a cheap copy. But if you're into a "dark" male lead who's also a vampire, and a pure, positive heroine, then try either or.
Chiyuki is a young girl with a terminal disease. Near death, she meets a vampire named Touya and blackmails him into spending time with her; however, he doesn't drink blood because if he took a blood partner the partner would die long before him and he doesn't want to get hurt. When Chiyuki is dying he saves her life by having her drink some of his blood, because he feels even being with her for a little longer will be enough. She returns to school and forces Touya to join her there, where they discover that one of their classmates is a werewolf who is ashamed of being a monster. Both of them slowly become closer to Chiyuki because of her warmth, her will to live, and her non-judgmental love which heals the wounds from their pasts.