Quote from jedinat
Take any completed series and read a chapter a week....
Seriously though, I don't get your request. It seems to obscure merely not wanting to have to wait month/years for the rest of the story... in which case you are excluding so many completed manga...
Yes, you've missed the point of my request. This requests excludes completed manga because they are completed and chances are I've read them or decided not to. A completed series I can hammer out in a week or less depending on the size and then I am left with nothing again.
I want to find series that are consistent in their releases as I've found so many that are good but are released sporadically and what seems like at random (for various and understandable reasons). There is just something to knowing that on Wednesday (and sometimes Tuesday like this week) that I will get a new chapter of Bleach, Naruto and One Piece to read and on Friday or Saturday I get Fairy Tail and used to get Medaka Box. Then during the week there is a spattering of things like Denpa Kyoui and Nosekoi that are released weekly but not necessarily on the on the same day every week.
A completed series I can sit down and read all at once which is great, but having something to look forward to on certain days is what I'm looking for so if I hit a spot where I'm looking for new completed series to read I know I have these ongoing series to fill time.
Also, taking a completed series and reading a chapter a week, come on, really...really...really? No one is going to read a chapter a week when they have the whole thing. I'm not going to exclude on-going series just because something is finished. I can wait months or years with no conclusion because that means for months or years I have something entertaining to every week.