Kami nomi zo Shiru Sekai, Denpa Kyoushi Recommendations
Both these serialisations follow male otaku who are "employed" to use their specialised knowledge to help others. They mostly help female characters, which subsequently result in a harem.
It's like a crossover of Kaminomi with GTO (or other awesome-teacher manga/anime). And the execution was awesome!
Main character is a genius otaku that only pay attention to his hobby, but they are forced to do another thing. In this task they help people, mainly girls, and the girls fall in love with the main character.
Similar otaku protagonists who are anime/eroge fanatics. In both manga, the protagonist helps others around him by solving their problems using game tactics.
Focusing on a genius protagonist, both series chronicles a young man as they take on the role of a conqueror. What they conquer are not territories but rather problems revolving around girls/students.
Both manga likes to play out their stories in experimental format. In essence, each story and arc focuses on various aspects involving result of success/fail ratios. There's a decent amount of drama, comedy, and potential romance. The main male protagonist is mostly devoted into their duties although can be distracted by abnormal events. And based some events, somecharacters that meets such a genius develops feelings towards him.
super otaku helping girls and getting his own harem
Both mangas are about a genius otaku in school (great grades but extremely addicted to games(Keima) or anime (Kagami)).
Both have the school setting, the difference is that Keima is a student while Kagami is a teacher.
They are both entertaining and funny ^^
Both manga are about an Otaku who is forced to do a job which leads to him having to solve some people problems and gaining their trust and love which builds up a harem.
Denpa Kyoushi is literally The world god only knows + Great teacher onizuka
Amazing Romance, Protagonist does a thing for the love victimss and captures their heart, Every Arc has another girl to conquer
Both male protagonist are otaku geeks.
Both have a same goal; conquer what they need to (Keima conquer girls) and (Kagami conquer students with problems. they are quite well-known in internet for otakus.
Both mangas are top 100 in mangafox.com
Both lead male protagonist have at least 1 side assistant.