Gourry's Scream ^_^
When Gourry remain a week whitout food, he become like the famous painting by Edvard Munch.

Bird-Horse
The birds used as mount by Gurabos and Jiras seems too be taken from the Chocobos from the Squaresoft's Final Fantasy RPG Series.

The Desert Village
The desrt village inhabitants resemble the Jawas ; beings living in the desert planet Tatooine from the film StarWars.

The Sword in the Stone
Where could a magic sword be if not knocked into a stone like Excalibur? ^_^

Giant Worms
These giant sand worms resemble the ones inthe film Dune.

Jiras and the Hikari no Ken
When Jiras manage to take possession of the Gourry's sword the light take a shape that's a mix of a fox head and a flame. So the running Jiras resemble a olympic torch bearer.

The Molten Clocks
In this scene there's a citation to a famous artwork made by Salvador Dalì.

DarkStar
For many details, DarkStar resemble to the creatures of the Aliens film saga.

Lina in Wonderland ^_^
This episode is a full citation to Alice in Wonderland.

Ghost in the vase
The captain of the ghost ship is imprisoned in a vase like the "Mago Pancione Etcci"; (I've no idea of the original title ^^;;;) also the vase resemble the one of that anime.

Sailor Gourry 3 ^_^
For the third time Gourry is combed like a Sailor Senshi, but this time he's dressed like a mermaid.
Note: These contaminations between Gourry and Sailor Moon are present in all the 3 series in the epysodes #17 ^_^ (v. 1st Series #17 and Next #17)

Gourry and Andromeda
Still in this scene Gourry is chained to a rock just like Andromeda (Saint Seya) and furthermore Gourry fights against the sea monster using the chains as weapons.

Kereru
In this episode there are also a succession of citations from "Neon Genesis Evangelion": Kereru (the boy who loves the fish girl Laila) is like Kaworu Nagisa.

Laila
It go on with Laila, the fish girl, that after the transformation to a human resembles to Rei Ayanami (except for the hair color).

Amelia and Asuka
Amelia wears the same dress as Asuka Soryu Langley in the episode 8 of "Neon Genesis Evangelion"

Laila's Father
Then Laila's Father resemble to Gendo Ikari, the citations is particularly evident in the settei in the picture, taken from the 3rd Slayers Try Artbook that show us what was his original look.

Young Laila's Father
At last, in a flashback we see how was Laila's Father when he was young, there are some likeness with Shinji Ikari.

The justice's paladins
The group of the 5 old defenders of the justice, that encounter Gourry e Ameria, is similar to those in Power Ranger style.

Searius
This character physically resemble to Vegeta from DragonBall.

Energy Attacks
Elrogos and Vege... ehm... Searius use some energy shoots in DragonBall style.