Suzumiya Haruhi no Yuuutsu, Robotics;Notes Recommendations
Both series' are comedic with a blend of seriousness.
Both series' female main protagonist leads a club with their own reason.
the other series is revolves in magic and supernatural, while the other one circles in science and technology.
Both feature a cynical, sarcastic male protagonist who ends up in a club with an energetic girl enthusiastic about sci-fi (Haruhi about aliens, time-travellers and espers and Akiho about robots) and eventually gets swept up in a paranormal conspiracy that threatens the entire world. The characters in general are very similar:
Itsuki= Subaru (sort of)
In my opinion, "Haruhi Suzumiya" is a lot better.