The Hammerspace nature of the Doctor's pockets on Doctor Who is well-established.
In "The Ambassadors of Death", the Third Doctor temporarily hides a reel of tape by sending it back in time, via unclear mechanisms. It reappears back in his hand when he needs it later.
The Fourth Doctor's pockets are one of his gimmicks, stemming from his Harpo Marx inspirational pedigree. A regular gag would be Doctor being captured and hauled before some malevolent middle-managementMook, who would inevitably order him to "Turn out your pockets", allowing the Doctor to fill the table with an endless collection of ludicrous items until his interrogator got bored. (See "Robot" for the first use of this gag and "Genesis of the Daleks" for him doing this to annoy space-Nazis). As his tenure wore on the items stowed away in his pockets got increasingly ridiculous, culminating in a Season 17 scene where he apparently stashes a half-full cup of tea into his pocket with no apparent ill effects. One of the novels even refers to them being a "pocket dimension".
In the spin-off novelThe Dying Days, after being pushed out of a plane in flight he survives by using the contents of his pockets to improvise a parachute.
At a crucial moment "The Runaway Bride", the Doctor produces a remote control to stop the robots that are attacking them. "Guess what I've got, Donna? Pockets!" he says, and when Donna says that the remote control wouldn't fit, he adds, "They're bigger on the inside." So is the TARDIS, of course.
In one episode, Rory takes a flashlight out of his pocket. The Doctor pulls out a fluorescent light that's almost as long as one of his legs. Rory is a bit put out that "[the Doctor's] is bigger."
The Series 8 episode "Flatline" has a variant: Due to the Monster of the Week's powers, the TARDIS has shrunken with the Doctor inside, so much so that Clara can carry it around in her handbag, leading to the Doctor helping her through the episode by handing her various tools through the TARDIS's door, making it look like she pulls them out of her bag. At one point the Doctor even gives her a large sledgehammer.
In Series 9, The Doctor steals Davros' (yes, that one's) chair, fixes himself some tea, and wheels out into the room full of Daleks.
"Of course, the real question is, where did I get the cup of tea? Answer? I'm the Doctor. Just accept it."
The Canadian comedy series The Red Green Show used Hammerspace in the Adventures with Bill sequences where Bill would often pull impossibly large items out of his overalls. Some examples include oars and a ten-foot ladder.
All That - Baggin' Saggin' Barry has whatever you need at any given time in his oversized pants, up to and including Abraham Lincoln.
On a 12th season episode of the British automobile Magazine ShowTop Gear, presenter Jeremy Clarkson seems to pull a hammer out of nowhere in order to demonstrate how sturdy the body of a Soviet-built Lada is.
Stephen Colbert's C-shaped desk is only ever shown from the front, which allows a ridiculous amount of junk to be pulled out of hidden cupboards as the plot calls for it. Notable items include a phone, a fax machine, his gun Sweetness, the Big Red Button, a pitchfork, a suitcase, John Oliver, at least two skulls, a variety of Prescott Pharmaceuticals products, Rahm Emanuel's severed finger, a secret prison (now closed), a pyramid (incomplete), a green room housing Michel J. Fox, a giant washing machine, a Foot Locker, a Starbucks, and another Starbucks. This in turn has given substantial credibility to the theory that Colbert is a Time Lord.
Lampshaded when Jon Stewart dropped by with an edifying videotape. "Let me just pop this into the part of my desk that plays VHS tapes..."
In the 2008 presidential primaries season, Mr Colbert interviewed the candidate Dennis Kucinich, who pulled an amazing amount of stuff out of his suit, including a full teacup.
Freshman sidekick Jerry Steiner on Parker Lewis Can't Lose had a trench coat with this property. Also, everything stored within was held in place by Velcro.
Constantly happening in Blake's 7 due to the tight-leather outfits of the heroes. In one episode Dayna uses a small robot bomb on wheels, despite not teleporting down with any form of bag or container to hold it.
In Skins, this is the only place Emily can possibly be hiding the Distraction Cake. In order to defuse an awkward situation at a party, she says "Hey, look what I made!" - and produces, from seemingly nowhere, a two-foot wide chocolate gateau.
Power Rangers does this sometimes. Rangers are eternally calling the name of a weapon, and then the scene will them change to them raising it as if they had it all along. Explicit teleportation of weapons happens just often enough to make it the logical explanation. And then there are the occasional cases where a character goes gets an item, is then not seen with the item, but does the "jump-cut to them raising it to use" trick. Apparently, you have to procure an item in real space to be able to retrieve it from your personal hammerspace.
Though the rangers aren't the only guilty ones. In the original incarnation, in the episode "A Bad Reflection on You", Rita decides to use the Psycho Ranger trick to frame the Power Rangers. She does it first in their human forms, landing them in detention. Bulk, who is apparently used to detention, first demonstrates this trope with his lunchbox, about the size of an average one. It starts getting impossible when he pulls out a submarine sandwich. Then, a bit later, he pulls out a "Detention Survival Kit" that has a TV in it.
In the first episode of Power Rangers Dino Charge, while Tyler and Shelby are facing a monster, Tyler reaches into his backpack and pulls out a banana, a pair of underpants, and finally, a shovel.
The morphers for this particular season are also kinda bulky blasters and exist in hammerspace pretty much by necessity.
In one episode of Bones, Brennan — dressed up as Wonder Woman for a mandatory costume party — suddenly has her (big) gun drawn while she and Booth enter a building where a hostage is being tortured. Booth's response is "Where'd you even find a place to hide that?" to her apparent use of Hammer Space.
The demon Sweet in the musical episodeOnce More With Feeling seems to be able to bring scrolls and doors from nowhere.
Kamen Rider does it, most prominently in the seasons where the Riders' powers are tech-based. Two stand-out examples:
Kamen Rider IXA'sTransformation Trinket is a knuckle device that docks into the belt, but for all intents and purposes the knuckle is the only part that matters. On several occasions, the knuckle is stolen, which allows whoever stole it to become IXA, with the belt just being on their waist with no explanation (as opposed to Kiva's, which does have a special effect for appearing around his waist).
Kamen Rider Double's trinket is similarly two-part, consisting of a belt and memory sticks-like devices that allow form changes. The two individuals who become Double each hold onto three of the six Memories, but when they transform, all six end up with Double who pulls them out of thin air to change forms. Kamen Rider OOO, which has even more transformation trinkets (coin-like objects) than Double, subverts this by the main characters needing to have the many Medals carried around in large containers or by a second party to switch them in and out (for Core Medals) or to resupply (for Cell Medals).
Kamen Rider Fourze is a very straight example, as the main character will have a total of 40 switches by series end to allow for different weapons and forms, and already pulls them completely out of thin air when in a fight.
Mission Control actually carries a briefcase which can hold up to 10 Switches at a time. However, when he first transformed into his Super Mode, the same case managed to release ALL the Switches, so it's still played straight. As for the Modules that are produced by the Switches themselves, it was mentioned that they are actually a manifestation of Cosmic Energy, making that bit more a case of Green Lantern Ring.
In multiple series (including Double and Kamen Rider Den-O), the Riders de-transform simply by unbuckling their belts...which subsequently disappear along with the rest of the costume. And yet the belts and all associated items reappear in the heroes' hands whenever they need to change.
Kramer's apartment on Seinfeld
Often invoked to explain where Immortals produce their swords from in Highlander. There's a running fanwank about 'swordspace' in their longcoats or other clothing. Amanda doesn't even bother to be that subtle about it, seeming at times to pull her sword out of her hair...and she's got very short hair.
The Middleman's title character seems to have pockets that lead to Hammerspace. He spends several moments removing increasingly improbable weapons from his pockets in the first episode.
On Star Trek: The Next Generation and Star Trek: Deep Space Nine, both Riker and Worf have produced phasers from seemingly nowhere. Not a tiny type-I "cricket" phaser that's designed to be easily concealed, but a full-sized type-II phaser. Notably, Starfleet uniforms don't actually have any pockets, so where they're being kept is anyone's guess.