Archive of Our Own (AO3) is also a great place to find such fanfiction. There are many well - written and creative 'yu yu hakusho crossover' stories there. The tagging system on AO3 makes it easier to filter and find the specific crossovers you're interested in.
Another option is Wattpad. While it has a wide variety of content, you can find some unique 'yu yu hakusho crossover fanfiction' there. However, you might need to do a bit more searching as the site has a lot of different types of stories.
Chapter 839, "Because There's a Good Show to Perform", is the clearest early answer because it turns Shi Lei's situation into a concrete plot event.
Chapter 649, "Where Did the Wild Wolf Come From?!", is the clearest early answer because it turns Shang Shuyue's situation into a concrete plot event.
Chapter 486, "So It's All Set Up, Right? Then She Will Set Up Too!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Hearing Jiang Li's words, the audience in the live stream was also...
Chapter 567, "Distant Nephew, Long Time No See", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from After separating from Jiang Li and the others, Team L headed in the...
Chapter 656, "If he's the grandson of the richest man, then I am the richest man!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event.
Chapter 852, "Could That Be an Aphrodisiac Spell?", is the clearest early answer because it turns Xu Ning's situation into a concrete plot event. The chapter turns that into something concrete by moving from Rong Junsheng's words startled Shi Lei and Rong Kexi.
Chapter 778, "The Gift of Being a Director", is the clearest early answer because it turns Ling Bei's situation into a concrete plot event. Early on, Shiguang, I really misjudged you, you're actually this kind of....
Look to Chapter 8 for the clearest answer. It begins with The resentment that had barely calmed among the crowd surged back two..., keeps building through Some of them were relatives of the Jiang Family, who felt it improper to..., and lands on Other people with a handsome and charming appearance.
Chapter 643, "Jiang Li Dominates the Trending Searches!", is the clearest early answer because it turns Trending Searches's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Qi Tianyu joyously carried his construction to the side to wait for...
Chapter 562, "So You Are Not First, But Last?!", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event. The chapter turns that into something concrete by moving from After they finished preparing the fish, Guo Xing and Luo Xuan got...