about new hero replacing old hero of a series (like DBZ etc.)!

I don't know whether some of you have noticed that many Japanese Anime/Manga artists tend to replace their main character by a younger one and mostly fail because the fans are pretty dissatisfied with losing their "heroes" of a series. Dragonball Z is one of the best example when Akira Toriyama decided to replace Son Goku by his son the teenager Son Gohan during the cell Saga. And when the following Boo Saga advanced, you could notice that the importance of character switches back to Son Goku who was again more powerful than Gohan and defeated Boo in the final.

In Transformers Generation1 (original US-series) they decided to replace Optimus Prime (Ginrai Convoy) with Rodimus Prime (Rodimus Convoy) right in the animated Movie and the Season 3. But in the end, Optimus Prime came back twice during Season 3 because the fans wanted it happen.
In Japan, the Transformers:Headmasters series was ignoring season 4 ("Rebirth") and made Optimus Prime dying again making Rodimus Prime the Autobot leader again. When many fans saw that, many were p****d off seeing their alltime hero dying again.

In both animated series, the attempt of replacing an old character with a new one failed. But this also happens in video games!

In Metal Gear Solid (2) it was Raiden replacing Solid Snake, in King of Fighters 99, it was K' replacing Kyo Kusanagi.

I guess, once a character is so much attached to your heart, you won't accept any replacement

Goku will always be the hero of DBZ and dagonball i hated it when he switched with Gohan he was wet whistled and it wasn't the same he didn't have goku's pride or fighting spilt for a start

and Raiden was such a woose he might have had some merit if it hadn't been for rose MGS IS Snake it was almost unberable not to have him 3 was bad enough but at least he was basicaly like snake

i have alwasy found that a replacment hero is never as good as the original its like replacing Cloud

You become attached to the person and a new hero just makes you dislike him becouse he is takeing away the hero you loved

though one exception i can think of is Yu-Gi-Oh GX becouse i thought Jaden Yuki was better then Yugi

fully agree with you,
Gohan was nice as a kid, but when he became a teenager, he was not much interesting character. He never could beat Goku's sympathism, fighting spirit. IMO Gohan also was less charismatic than Vegeta.
Gohan is powerful, yes, but he lacks the heart of being a true warrior.
I also hated him for being responsible of Goku's sacrifice when he disobeyed his father by not killing off Cell, causing Cell to self-explode.

As for MGS: Raiden was too smooth and clean, not that bad-*** attitude like Solid Snake. Too bad that we might not see Snake again after MGS4 where he seems to die because of Foxdie.

Iam so mad over that what is Hideo Kojima thinking he never does what the fans want and becouse of that he gets nothing but complaints

MGS3 had its stupid moments too sometimes the MGS games can be so disapointing becouse Hideo Kojima push's the story beyond the limits of the game

IMO MGS3 was overall very good but sometimes the story content seems to be overlooked the older Metal Gear games. At least MGS3 had no more so many codec sequences like MGS2 when I was bored after the first time. MGS2 is more watching than playing which is a big factor why many gamers were not very satisfied.
I also think that MGS3 should be named MGS Zero since it takes place in the 1960's and even does not tell the story of Solid Snake but his genetic father Big Boss.