Tegami Bachi. The ending left a lot of questions unanswered, but the story was really interesting and the visuals were beautiful.
Bakuman: Done by the same two people that made Death Note. I read the first few chapters of the manga and all the chapters that SJA had. I haven't seen much of the anime, but, from what I've read, it's one of my favorite manga ever. The story is really good and I love the art style.