Classic. One of the few shows I loved as a child, came back to as an adult and appreciated it even more.
Yusuke is my favorite male character in anime. On one hand he's a bully who taunts his opponents before during and after he beats their ass. Doesn't give a fukk about your honor and respect. Watching him versus any villain is top notch entertainment because you know he's about to drop some funny one liners somewhere in the middle of shoving a spirit gun down their throat
but Yusuke is also sensitive to criticism from those who don't try to understand him, and protective of his few friends who do care about him. When any of those people are on the verge of dying, or do die, he responds as if he is dying. And he's not alone in that - Kuwabara (especially), Hiei, Kurama, Keiko, Genkai, all try to protect his back as a way of rewarding his loyalty to them. Wouldn't hesitate to put their lives on the line because they knew Yusuke would do the same for them. There are a lot of strong bonds in YYH that grow over the course of the series, to a point where rivals become as close as brothers. Even some of the villains grow to respect him, like Toguro who sees a lot of Yusuke in himself.
Yusuke uses fighting as a way to find purpose for himself in a world that otherwise rejects him (teachers try to get him and his friends expelled, father walked out on the family, mother is a alcoholic), and he slowly does achieve that the more people he encounters throughout the story. By the end he has a fully explored character arc where we see him progress from a boy with no direction in life to in the end a man who has full confidence in his sense of self and is surrounded by lifelong companions. In all he's one of the realest shounen leads out there, easy to admire and identify with in some way. You can make the same analysis more or less for the other members of Team Urameshi who are well explored in their own right.
I totally disagree that the ending of YYH is bad. Weaker than the other arcs, yeah. But It serves it's purpose of completing Yusuke's character arc - to find the origin of his powers and meet the man who effectively serves as his father. We get to see Hiei's backstory (how he got the third eye, his mother, what he was like as a child) as well as Kurama's. In the end we see Kuwabara post graduating high school and studying for college - the impact that Yusuke has carried on his life is evident, and we see him and Keiko hook up after all that dancing around the topic of their relationship. He told her he'd come back to her and kept that promise in the end.
It's a great ending all things considered.
Easy 10/10 anime. In my top five all time only clearly below Legend of the Galactic Heroes and Ashyta no Joe.
nominating Neon Genesis Evangelion and Prison School