When it comes dream sequences, no medium can equal the sheer scale and imagination that can be conjured in video games. Whether its hellish nightmares out to haunt the dreams of players or more grounded, real world sequences that delve into the personality of the character you're playing, dream sequences always shake-up and add an extra layer to any gaming experience.
So its no wonder why some of the most memorable sequences in gaming as a whole come from dreamlike moments of gameplay. With the ability for the developers to shake up established mechanics, these levels give the player the ability to do ridiculous things they'd never expect to see in an otherwise grounded game. Failing that, they can simply act as a nice change of pace from the regular experience of a title, and their idiosyncratic nature can offer a much needed break from the action in favour of a section dripping with atmosphere or character.
The best part however is that, unlike films or television, the unreality of games themselves make it much easier to mask the fact that what you're actually playing isn't actually happening. Through subtle tricks and techniques, gamers can be non the wiser when they're playing through a dream or hallucinatory level, which makes it all the more satisfying when the developers decide to pull the rug straight out from under them.