The Rice Cooker from Dragonball, containing Piccolo Daimao.
Majin Buu’s egg, from Dragonball Z.
Cell’s Egg.
The storage pods of C16, C17 and C18
The Dragonballs themselves.
The Capsule Corp Capsules.
The magic lamp containing a Djinn.
The Cursed Sarcophagus containing the Doom Slayer.
The stasis modules on board the Botany Bay containing the frozen Khan Noonien Singh.
The modified transporter system aboard the USS Jenolan, holding the dematerialised Montgomery Scott in its pattern buffer.
Uzumaki Naruto’s belly, containing the Jinchuuriki.
The Clow Cards from Cardcaptor Sakura.
The time travel transport pods from Hinamatsuri.
The compression marbles of Mr. Compress from Boku no Hero Academia.
The DISKs from Marvel Disk Wars, that contain the Marvel Superheroes.
Various cages and floor circles and warding symbols of salt and blood and whatever to contain demons and angels and so on in the TV series Supernatural.
Star Wars light sabers are limited to a blade shape by a containment field
Have you heard stories of Alladin and magic lamp? Magic lamp was the container for the spirit. By rubbing the lamp it will come out and do whatever he says.
The horcrux containers in Harry Potter.
The jewel hanging on a collar worn by a cat in Men In Black contained an entire galaxy, leading to a whole “Orion’s belt” mystery.
Speaking of jewels, I seem to remember some kind of sinister thing trapped in a red jewel on a Star Trek episode.
The many types of “hibernation” pods in various SciFy stories.
The refrigerator that saves Indiana Jones from an atom bomb explosion.
The face of Boe in a giant glass case on Dr Who. The TARDIS.