What Are The Notable Differences Between Hunter X Hunter In 1999 ...

I'm a Japanese, so please excuse my English.

I ignore a lot of small changes, and want to talk about the cause.

Speaking from the conclusion, the notable differences are the following, I think:

1. Original Manga's Progress
2. Broadcasting Station
3. Main Target

1. Original Manga's Progress

Togashi is working now. That's all.

2. Broadcasting Station

Fuji TV is following One Piece, Toriko and Dragon Ball. It is the HxH 2009's station, and faithful to the original. Fuji's slogan is "NO FUN, NO TV", and is known as the most vulgar TV station in Japan. But I really, really love Fuji's "noitaminA".

The 2011's Nippon TV is the most traditional commercial broadcasting station. This oldest station is known as the most aggressive technical pioneer. Maybe the original fans hate their editing, and the children's parents like it. I think that the 140 times same OP songs is their attempt, too.

3. Main Target

In Japan, HxH 2009 was the "Saturday Golden Time Anime"; then from episode 62 onward, it became OVA. HxH 2011 was the "Sunday Morning Anime"; then from episode 99 onward, it became "Midnight Anime". Both began broadcasting in time slots meant for "Children's Anime" in Japan, and OVA and "Midnight Anime" were the "Adults' Anime".

The nature of the children's time slot is slightly different between the two continuities. "Saturday Golden Time Anime" means that children watch the anime with their parents at dinnertime. "Golden Time TV Program" is the TV Program that airs between 18:00 ~ 20:00 in Japan. If the Golden Time Anime airs on Saturdays, TV station is expecting the conversation with the children. In other words, children logical conversation with the parent is satisfied are eligible. This is why HxH 2009 did not refrain from grotesque representations, in contrast to HxH 2011. The reason why the TV broadcast was finished is because the original stock was gone. By the way, there is no relation to the animation named "Golden Time".

On Sunday mornings, I think you are still sleeping, right? In this time slot, most young children are watching TV, so a more wholesome animation is required. Japanese parents do not like their children watching torn heads or hearts or fingers without supervision. I think the reason of the change in time slot is that there are few parents who like their children watching torn organs in anime. Then I wonder what kind of adult gets up in the early Sunday mornings, but I do not have the answer. I think they are probably also the type that does not turn on the TV during dinnertime.

Anyway, I do not write in detail because spoilers, but HxH 2011 thoroughly ignored the content of the original manga. I'll never forgive the corruption related to Kite, the worst difference for me:

In the original manga and the 2009 anime, the reason why Gon aimed to become a hunter is because Kite told him that Gon's father is a superior hunter. Gon thought his father was dead. First appearance: Kite gave Gon a scolding "you should not come near the territory of dangerous organisms". In the 2011 anime, Gon has forgotten the existence of Kite, and they don't know each other, not even the names. First appearance: Kite had been fishing on the side of the nests of chimera ants.

For more information, you can read this wiki.