Who was the first writer/movie director/artist that came with the idea of the zombies we see in movies nowadays like Resident Evil, World War Z, Walking Dead? In general: the idea of a person seemed dead but that walks and just bites people and then turn them into zombies as well.
It seems very widespread now, but I don't know where does it came from. Was it a book, a movie, a computer game? Was Resident Evil (as far as I concerned, the first one to introduce this type of undead?
At least in film, the first "modern" zombies, the literal dead walking again (as opposed to voodoo and other drug and / or hypnotic states) appear a couple years before Night of the Living Dead. A Hammer film from 1966, Plague of the Zombies, was the first film to show corpses rising out of their graves, digging through the earth, to walk again.
While this is the herald of the modern "truly-dead" zombie, it wasn't until 1968 and George A. Romero that the idea of the "real" modern zombie (actually dead and eating the living) appeared and took root. The fact they weren't called zombies is moot. They were zombies as sure as Nosferatu was a vampire. Also this is only taking into account multiple numbers of zombies. I don't know the earliest film (or other) reference to a singular cursed or other-wise revived person.
And as for Gilgamesh, that is more parable or metaphor. It is not the dead being brought back as rotting corpses (admittedly my understanding of the Epic is sketchy at best). It seems to be the dead being released. I do think there is a difference. Same reason people generally don't think of Lazarus or Jesus to be zombies.
This one seems to go back to the Epic of Gilgamesh; see http://www.ancienttexts.org/library/mesopotamian/gilgamesh/tab6.htm
I will knock down the Gates of the Netherworld,
I will smash the door posts, and leave the doors flat down,
and will let the dead go up to eat the living!
And the dead will outnumber the living!
This contains most of the core ideas; zombies rising from the dead and eating living people are all here. It's a full-fledged zombie apocalypse right from the dawn of literature, in other words.
The idea of an undead creature that bites a living person thereby turning them into another undead is certainly from the vampire myth, which is - again - older than dirt (obligatory TV Tropes warning).
The idea of the modern zombie, i.e. a horde of reanimated half-rotten corpses that try to eat the living and (sometimes) convert their victims to new zombies, usually accompanied by the collapse of civilization as a setting, is sometimes acknowledged to have been invented by George Romero in his movie Night of the Living Dead.
From Wikipedia (emphasis mine):
Romero revolutionized the horror film genre with Night of the Living Dead; according to Almar Haflidason of the BBC, the film represented "a new dawn in horror film-making".The film has also effectively redefined the use of the term "zombie". While the word "zombie" itself is never used - the word used in the film is ghoul - Romero's film introduced the theme of zombies as reanimated, flesh-eating cannibals. Early zombie films like Victor Halperin's White Zombie (1932) and Jacques Tourneur's I Walked with a Zombie (1943) concerned living people enslaved by a Voodoo witch doctor; many were set in the Caribbean.
Romero himself is said to have been influenced by the book I Am Legend, where the creatures are actually vampires.
