I haven't had a lot of time to come online, recently, which is why I didn't respond to this thread sooner. But, let me just say that Yu Yu Hakusho is BY FAR my favorite shounen anime, one of my favorite anime in general, one of my favorite cartoons in general, and just overall one of my favorite TV shows ever, period.
As for the whole dub vs. sub thing, all I'll say about that is that while I initially was really biased towarRAB the sub, I have now seen mosto f the series in Japanese with subtitles, and have really grown to appreciate its great voice acting, especially with the voices of Hiei and Kuwabara. However, I still have to say that I personally prefer the English dub, partly because that's the version which I grew up watching on Adult Swim and Toonami, and also partly because I personally find its jokes to be much funnier than they are in the sub for Yu Yu Hakusho. Also, Justin Cook's voice for Yusuke pretty much makes the dub for me. I agree with the people who said that he deserves an award for that particular role. And, honestly, it wasn't really all because of his witty humor or one-liners, but moreso because I just felt that this tone fit Yusuke's character perfectly for most parts in the series (there were a few scenes where I felt that he could have doen some better voice acting, but overall, I have very little to complain about when it comes to his portrayal of Yusuke). As for Nozomu Sasaki's Yusuke voice, I do like it, but it just doesn't grab my attention as well as Cook's Yusuke voice does (but that's just my personal opinion).
Anwyays, if I had to say what I liked best about this series, it would easily have to be its brilliantly characterized cast. I love the main 4 characters, I find a lot of the supporting characters to be well done and memorable as well, and I also find the villains to be fantastically characterized as well, particularly ones like Sakyo, Younger Toguro, and of course Sensui (with each of this awesome personalities that we get to see ).
I'm actually of a somewhat opposite opinion. I actually feel that it goes way up in quality with the Chapter Black arc, simply because that arc proves that YYH could focus more on story than fighting and still be really entertaining. Overall, that has to be the best-written arc that I have seen out of any shounen anime, personally. I do agree with people who feel that the show went downhill with the Three Kings arc, though, but it was still relatively entertaining, and there wasn't anything that I really disliked about it, aside from the fact that it was insanely rushed.
Even though I'm not a big fan of the movies, I've always wanted them to dub them just so I can hear some more awesome performances from at least the main English dub cast of the series. However, I have really lost most of my hope for that ever happening, since it doesn't look like FUNi even has any interest in the series anymore, which is probably why they haven't even attempted to license either of the movies at all (besides, if they were going to, I'm pretty sure that they would have done it by now).
But, maybe if enough people express to FUNimation that they would really want to see them license the movies and give them a proper dub, they might actually go for it (but I still highly doubt that it would be very likely to happen ).