These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Leo's voice actor in the dub, Greg Ayres, is well known for his jokes about Christian Slater's acting career and it even became a slight Running Gag in the dub, as he mentioned "Christian Slater's career" when listing the people boarding the ferry to River Styx.
"Funny Aneurysm" Moment: The joke with Reiichirou and the Merry Mary doll becomes a lot less funny when you learn that his voice actor Illich Guardiola was arrested in 2014 for sexual assault of a 16 year old (consent age in Texas is 17).
Growing the Beard: ADV's Gag Dub is okay early on, actually staying fairly close to the original script in the first two episodes, becoming a bit looser in episodes 3 and 4. Episode 5 and onward is where they really start to improvise and where the dub hits its stride.
Hilarious in Hindsight: English dub episode 19, "Please stay tuned for probably the hottest homosexual newscaster on the planet, my friend, Anderson Cooper." This came out six years before Cooper publicly outed himself.
Memetic Molester: Babasare. Seriously what is the reason of her appearing only to children?
Mis-blamed/Misaimed Fandom: ADV Films occasionally catches flak for the personality changes in their Gag Dub of this series. Actually, ADV was told to do whatever it took to make the series sell... so they did.
So Okay, It's Average: The general opinion on the original Japanese version, and part of the reason it didn't catch on. Opinions on the Gag Dub, on the other hand...
Subbing versus Dubbing: Regardless what you think about the English dub, on the other hand the Spanish dub not only is a literal straight dub, but also a relatively mediocre one due to the changed names (the English keeps most of the original names) and wooden performances.note Although that was because in Argentinian Spanish it's very difficult to pronounce some Japanese words and names, compared with other Spanish dialects.note There is apparently confusion as to whether the Spanish dub was done in Argentina or Colombia.
What Could Have Been: There was an episode made but never aired (and probably never recorded by the seiyuu) revolving around the kuchisaki-onna, a female ghost with a disfigured face. It's supposed to look like a Glasgow Grin but the anime depicted it more like a cleft palate. In order to avoid offense, the episode was shelved. Can you imagine what ADV's Gag Dub would have done with that material? On second thought, maybe it's best that it never saw the light of day.
Greg Ayres expressed regret that the Mel Gibson Jew rant happened just a few weeks after production wrapped, as he would have loved to have incorporated it into the final episode.