Total Recommendations: 3
Both are psychological mangas. They start with a weird premise and as the events unfold the plot becomes more and more fucked up.
There are some similarities regariding the characters Adagaki is the tsundere character (Chitoge) Yoshino is her servant (Tsugumi) Neko is the "rival" that appears out of nowhere (Marika) In addition to this, the MCs have stories related the past: Adagaki and Masamune were friends 8 years ago, but she doesn't remember him, Neko and Masamune knew each other, but he doesn't remember. Does this ring a bell? Yes, the keys and the promise from 10 years ago in Nisekoi. Also the setting is similar (but there are no gang/yakuza wars) and the shows share the comedy tag.
Both shows have supernatural elements and a slow but steady progression. While Bakemonogatari is divided into 5 arcs (with each arc focused on a definite character), Durarara!! starts by introducing the characters and their background and eventually everything connects throughtout the show with some crazy and unexpected development. Furthermore, in some episodes of Durarara!! Hiroshi Kamiya (as Orihara Izaya) is the narrator of the story, which heavily reminds Araragi's narration in the Monogatari Series (Araragi Koyomi has the same voice actor as Orihara Izaya).