NHK ni Youkoso!, Oyasumi Punpun Recommendations
Both can be hilarious, dark, insightful, disturbing and lighthearted all at the same time. They're both slice of life about a naive character dealing with the world around him.
Both deal with individuals surrounded by people and situations that are rather psychologically twisted. Both contain very similar types of dark/morbid humor, and main characters with rather "lively" imaginations. The lead females (Aiko/Misaki) also have very similar issues and situations.