One great anime is 'Sword Art Online'. The main character, Kirito, is extremely overpowered (OP). He is highly skilled in the virtual reality world of SAO. In the series, he also has a love story with Asuna. Their relationship develops as they face various challenges together in the dangerous game world.
Another common theme is the fish - out - of - water situation. The MC is transported to a new world, so they have to adapt to new cultures, magic systems, and social structures. In 'Konosuba', Kazuma has to deal with all the crazy things in the isekai world while trying to make the best of his situation with his OP party members. And they often have a goal, like saving the new world or finding a way back home, which drives the story forward.
Power progression is a common theme. The OP main character usually starts from a certain level of strength and becomes even more powerful over time. Another is the development of relationships with multiple female characters. They often start with misunderstandings or the main character helping the females in some way, and then relationships grow.
Sure. 'Overlord' is a great isekai novel with an OP main character. Momonga, the protagonist, gets transported to another world and has incredible power from the start. Another one is 'That Time I Got Reincarnated as a Slime'. Rimuru starts off as a slime but quickly becomes very powerful in the new world.
Sure. 'Date A Live' is a great 'op mc harem light novel'. Shido Itsuka has the ability to seal the powers of the Spirits, which are powerful female entities. He ends up in a harem - like situation as he tries to save the Spirits. Also, 'High School DxD' features Issei Hyoudou, an OP main character who is surrounded by a bevy of beautiful female devils and angels, making it a typical harem light novel.
One of the best is 'The Lord of the Rings' by J.R.R. Tolkien. It has epic battles, magic, and a vast world filled with different races. Another great one is 'A Song of Ice and Fire' by George R.R. Martin. It's full of political intrigue and intense combat. 'The Wheel of Time' by Robert Jordan also stands out, with its complex magic system and large - scale wars.
Well, 'Toradora!' has a unique love story along with an OP - ish MC in a sense. Ryuuji Takasu may not be the typical OP in terms of superpowers, but he is very capable in his own way. His love story with Taiga Aisaka is full of twists and turns. They start off as helping each other in their respective love interests which are actually each other in the end. It's a really cute and complex love story.