In my opinion, 'The World God Only Knows'. Keima Katsuragi is a dating sim expert who has to capture the hearts of real - life girls to capture escaped spirits. This leads to an expanding harem of different types of girls. Also, 'Nisekoi' is quite good. Raku Ichijo is forced into a fake relationship with Chitoge Kirisaki but along the way, he gets involved with other girls, creating a harem - like situation. And don't forget 'To Love - Ru', which has a large cast of female characters around the male lead, Rito Yuuki, with lots of comical and romantic situations.
Typically, best harem novels have a male protagonist at the center. For example, in 'The World God Only Knows', Keima Katsuragi is the main character. He is surrounded by multiple female characters. These novels often involve elements of romance as the male character gradually develops relationships with the female characters in his harem. There is also usually a central plotline that drives the story forward, like in 'Rosario + Vampire' where Tsukune Aono has to navigate his life in a school full of monsters while dealing with his relationships with the female characters.
One of the best is 'The Rising of the Shield Hero'. It has an interesting harem aspect where the main character, Naofumi, gradually gains the loyalty and affection of several female characters. Each character has a distinct personality and backstory, which makes the harem dynamic engaging.
One great harem visual novel is 'Clannad'. It has a beautiful story with multiple female characters that the protagonist gets involved with in different ways. The character development is deep and the emotional arcs are engaging. Another is 'Amagami SS'. It offers different story routes for the main character with various love interests, each route presenting a unique and interesting harem - like situation. And 'Date A Live' also stands out. It has a cool concept where the main character has to date spirits to save the world, leading to a harem - style plot with a lot of action and romance.
'I Shall Seal the Heavens' can also be considered. It has a unique take on the harem cultivation concept. The protagonist's journey of cultivation is complex and his relationships with the female characters add depth to the story. There are many plot twists and turns that keep the readers hooked.
One of the well - known best harem wuxia novels is 'Coiling Dragon'. It has an engaging plot with a strong male lead who gradually builds his own harem. The story combines elements of wuxia like martial arts, cultivation, and adventure, along with the harem aspect where different female characters with their own personalities are attracted to the protagonist.
'The Fruit of Grisaia' is also a top - notch harem visual novel. It has a complex plot that gradually unfolds as the protagonist gets closer to the different heroines. The art style is beautiful and the character personalities are distinct and interesting.
One popular one is 'The Rising of the Shield Hero'. It has elements that can be considered harem - like with multiple female characters having close relationships with the main character. Another is 'Date A Live', which features a male protagonist and a group of female characters in various interesting scenarios.
One great harem romance novel is 'The Demon King's Harem'. It has an interesting plot where the demon king finds himself surrounded by various characters in a harem - like situation. Each character has their own unique charm and backstory that adds depth to the story.
Well, in the best reverse harem novels, there is usually a strong female lead. She is often independent, intelligent, and has her own goals. For example, in 'The Selection', America Singer has her own ideas about love and the world around her. Another characteristic is the complex relationships between the female lead and the male characters. They may be friends, rivals, or have different levels of romantic interest, like in 'A Court of Thorns and Roses'. Also, there's often a richly built world. In 'Throne of Glass', the world of Erilea is full of magic, politics, and different cultures, which adds depth to the reverse harem relationships.