"GJ bu" 1-9 by Araki Shin. This is an amazingly consistent and balanced series.
The 4-page-per-chapter format is maintained from beginning to end, and there are almost no dull moments. While there is mostly no continuity between chapters, there is consistent character development, and the central theme of the story progresses through these character developments. No matter which volume you start on, all chapters have consistent quality and feel.
Just consistency alone might not make this series stand out from regular 4koma manga, but remember that this is a novel series. It is able to deliver greater information density than most manga through text, but at the same time it is more lightweight to read than most light novels due to the short chapters and copious illustrations. In this sense, it is very well balanced.
Also equally amazing is that the author knew when to stop, ending the series at the perfect moment, and did not drag on further. That said, there is a second spinoff series, taking place in the same universe as this one but with different main characters. Looking forward to that series.
This is a great series to read, especially for people with variable amount of reading time.
Previous (2013-04-29): "GJ bu" by Araki Shin
Next (2013-06-07): "Hikaru ga Chikyuu ni Ita Koro" volume 7 by Nomura Mizuki