The Irresponsible Captain Tylor (1993) is a fantastic parody of late 80s/early 90s sci-fi and adjacent genres like space operas, while developing a good story of its own. As the name implies, it very much subverts the trope of the wise captain making the best decision in the name of the crew and the big human space empire named something like the federation, and is a entertaining story. [Note: it's kinda horny at times, especially E1] The TV anime is a complete story, but unfortunately the sequel OVA is stuck with a "read the LN lol" ending. I suppose it suffers from the main driver of unpopularity, being old.

The World God Only Knows (2010) is a story that's got an eyebrow-raising premise, but is actually really good both in manga and anime form, with a slow-burn but good story, unique protagonist and lovely artstyle. Unfortunately the ending was rushed because the author was going through a period of bad health, but is still is good enough.

One day, someone with the skills, time and resources to do will start translating the Emblem Take 2 manga... I hope. The OVA is good shit, yet even with the relative lack of anime/manga serious yakuza stories and the popularity of the Ryu Ga Gotoku video game series, it hasn't happened yet.