In Love Hina, Kaolla Su builds a device so that people's dreams may be put on the television. Obviously, Keitaro suffers because of it.
Trinity Blood had one of these at the Vatican's disposal, but it was very painful for the witness and showed only picture, not sound.
Cowboy Bebop had the 'Alpha Catch', which showed the last thing a nearly-comatose bounty-head saw before he was hurled out a window.
Fantastic Four #27 has Reed build a "Thought Projector" that creates images based on the thoughts of the wearer. It is brought out of storage in #126 so Ben can have a Flashback to their Origin Story. Returned again so that Reed could communicate with a coma patient in an issue of Marvel Knights 4.
In Amazing Spider-Man #39, The Green Goblin used a machine to project images from his brain of his past battles with Spider-Man.
Kryptonian Thought Beasts used to do this in a Silver AgeSuperman story, showing what the person they were near was thinking on their triceratops-like forehead shields. They showed up repeatedly in Krypton stories. Often as not, the image depicted the beast's intention of stomping flat their targets.
Kryptonian society also rendered artists moot with their device that allows painting by thought.
One old short sci-fi story featured an auditory equivalent, allowing two people with electrodes hooked up to their skulls to communicate thoughts directly. IIRC, one end was designed to receive, the other to send thoughts. Several basic tests were run to make sure the thing wasn't a fluke or a placebo leading to an additional receiver being installed for confirmations. The story ends with a bit of a twist when they try hooking one receiver end up to the sending end directly in a loop. The scientist on the other receiver looks terrified and rips them apart moments afterward. Apparently, he heard the machine itself start to think...
In Ursula Le Guin's short story "The Diary of the Rose", a mind viewer is used against a supposedely insane engineer.
That's So Raven, "Vision Impossible": Raven's Clip Show er... I mean thoughts are projected onto a screen via a fancy machine.
In The Sarah Connor Chronicles, John Henry, a T-888 Terminator hooked up to an advanced AI, has screens that project images related to what he's thinking about.
There was an episode of Stingray (1964) where King Titan interrogated Troy Tempest using such a machine, without Tempest knowing it.
Quatermass And The Pit (TV and film versions) has a thought-visualising machine called an "optic encephalograph" that shows racial memories of Martian genocide.
The Prisoner episode "A, B and C" involves a machine that can read Number 6's dreams and memories, but by the end of the story he is controlling the images.
Other notable examples include the first Doctor being interrogated, but because he's being flippant, the screen shows only random objects, and the second Doctor's trial in "The War Games", wherein he mounts his defense by using thought projection to show images of the great enemies he has fought, including the Cybermen, the Daleks, and... The Quarks. Since the Quarks were a one-off and markedly crap villain — and not even the proper enemies in that episode anyway (they were just service robots working for the Dominators), it has become something of a running joke in the Expanded Universe that the second Doctor has a weird and inexplicable Quark obsession.
Another example occurs when the Second Doctor creates a mental projector with the scanner to explain to Zoey how traveling in the Tardis can be dangerous by showing her clips from "Evil of the Daleks".
Stargate SG-1: In "Out Of Mind", a machine is used to project holograms of SG-1's Clip Show memories. Like almost anything that shows up on the show, it makes reappearances in several subsequent episodes.
Red Dwarf: "Gunmen of the Apocalypse" projects Kryten's "dreams" onto a monitor.
Again in "Back In The Red" when a machine is used to probe the crew's minds to obtain evidence in their hearing.
Also used for an earlier joke in "Thanks For The Memory" when Lister and the Cat go to the room that generates Rimmer when he's asleep and can see what he's dreaming: singing a song while wearing a longcoat, tophat, cane, and...underpants.
One episode of House had one of these. I kid you not.
At least everyone else in the episode had a realistic level of skepticism. It's like only House realizes it's a TV show.
A bit of context: The patient was having unexplained seizures and out of body experiences. After running every diagnostic they can think off, they haul out a highly experimental "brain reader." They first show the patient a series of pictures, so the machine can analyse how her brain processes pictures. Then, when they ask her to think of one particular thing, they get a very fuzzy, very basic outline of her mental image. So, it's not exactly making a 3D hologram of her thoughts, but it seems plausible, maybe Twenty Minutes into the Future.
The best part was while everybody else is shocked that it worked at all and marveling at how amazing it is to be able to read someone's brain, Foreman is skeptical about the image itself being useful:
On I Dream of Jeannie, Doctor Bellows tells Major Healey they'll be monitoring his dreams while he's in the shuttle (presumably in terms of brain activity), he assumes it's this trope, and advises not to construe anything from his more interesting dreams...
Used in the clip show "A Blast for Buck" on the series Buck Rogers in the 25th Century on Buck.
Mystery Science Theater 3000: Had a skit where Joel hooked up Crow to a machine that revealed what the later was dreaming about on a TV screen. Turns out it's a hilariously embarrassing dream involving TomServo.
In The Goodies, Graeme Garden uses the power of the Cricklewood Computer harnessed to Bill Oddie's brain, via the interface of a sherbet dab, to project his train of consciousness onto a monitor screen. frequently this involves naked ladies and Chelsea F.C. but now and again throws up an insight which is useful to the boys.
Mandrake The Magician frequently does this as a means of painless interrogation. He hypnotizes the target to sit still and then literally causes their memories to appear on a wall like an old fashioned movie projection (usually revealing the villain of the week they worked for).
Calvin and Hobbes, Aliens abduct Calvin and hook his brain up to a computer monitor where they bring up all of Calvin's (incorrect) math knowledge and delete it from his cranium.
Call of Cthulhu supplement Cthulhu Now, adventure "Dreams Dark and Deadly". A dream research institute develops technology to read the dreams of sleepers, and can project them onto TV screens so others can watch them.
In Earthbound, after completing one of the late-game Sanctuaries, Ness's thoughts are projected and visibly scroll across a neon wall where he begins asking himself about his journey and his progress. This is one of only two times that Ness has dialogue in the game.
Researchers at the University of California, Berkly, are starting to figure out how to do this with the waking mind, by having a subject watch a video, recording what happens in their brain, then trying to re-translate it into video. While crude (you can find examples with a carefully worded search on certain popular search engines), the technique is still in its infancy, and could very well lead to dream mapping in twenty years or so...
Screen Projected Thought Machine, Mind Reading Machine, Mental MRI