Need to pick up and finish HSDK again, but yeah that one. Same for Oh My Goddess simply because as others have said, it was such a constant that you'd think it would run forever. As for the rushed feeling endings, I think it's due to the authors not quite having planned things that far and hitting the ground running. There have been some new manga that have kind of picked up the slack left by Naruto and Bleach such as Seven Deadly Sins, Kitetsu no Yaiba, Blue Exorcist and Seraph of the End, but they haven't even touched the levels of popularity.
Note: I left out Promised Neverland since that's very different than the above mentioned.