Be Kind Rewind: When the magnetized Jack Black goes into the video rental store, the camera warps and lines periodically to show that he's magnetized.
A subtle example in Pirates of the Caribbean: Dead Man's Chest. As Jack is sailing away from the Island of the Pelegostos and is giving his standard farewell speech, the wave that smacks Jack in the face and cuts his sentence also manages to hit the camera as well.
A literal example: for a scene in Tommy Lee Jones' directoral debut, The Three Burials Of Melquiades Estrada, he wanted a shot of a horse falling off of a cliff onto the camera. Due to budget restrictions, the only way he was able to do it was to literally place the camera at the bottom of the cliff and drop a fake horse onto it. He ended up destroying the camera and ruining some of the film, but hey, he got the shot!.
Happens unintentionally in Children of Men during an extended shot of a gunbattle, when a drop of blood from a squib happens to spatter onto the lens. Because the continuous shot is actually a number of shots stitched together with CGI, the blood discreetly disappears when the camera goes through fog.
Disney's Aladdin: "Please, please, come closer!" (Thunk!) "Too close, a little too close!"
Happens twice in High Anxiety, when the camera dollies though a window, which breaks. In this film, it's a parody of Hitchcock's famous move of dollying through a window without breaking it using clever editing and effects.
In Robin Hood: Men in Tights, while Maid Marian is singing in the bathtub, the camera smashes through the window, interrupting the song. It then cuts to a shot of the camera, which moves back outside. Later on in Men In Tights, we see the Abbot called to marry Maid Marian to the Sheriff walking down the aisle towards the camera until he ends up loudly hitting the lens with his staff.
Spaceballs has a similar joke, where the camera zooms in too close and hits Dark Helmet in the helmet. During Dark Helmet and Lone Star's schwartz duel, Helmet accidentally kills a camera operator on the set.
Helmet: Um... He did it.
In Space Jam, Daffy Duck spatters spit on the lens.
In another, PT Flea gives a frenetic speech and leaps into the air, hitting the (non-existent) camera, and LEAVING A SMEAR on the (non-existent) lens.
And when the circus bugs arrive at Ant Island, and land, Heimlich is unforunately descended into the camera.
This happens frequently in Cloverfield — in some cases, the jostling is so violent that the camera image becomes pixelated or the video skips (revealing the original contents of the camera's memory card).
Also, in the subway tunnel escape scene, blood splashes on the lens and Hud has to wipe it off.
In the ending of Monty Python and the Holy Grail, a policeman covers the camera with his hand, shutting it off. It's the last thing ever seen in the movie; there are no end titles or credits.
He put his hand over the lens as the cameraman came towards him. It still "broke" the camera.
In the DVD commentary, Terry Jones and Terry Gilliam remarked how in one of the initial screenings they saw of the film the audience assumed that the film had broken and simply sat and waited (probably waiting for the projectionist to fix it), not realizing that the film was, in fact, over.
In Alfred Hitchcock's The Wrong Man, after the title character has been incarcerated for the murder he did not commit, his disorientation is symbolized by having the camera slowly move in ever-increasing circles.
An early scene in Scary Movie has Cindy being attacked by Ghostface. At one point, the camera zooms in on her screaming face... only to conk her in the noggin.
In The Incredibles, the "camera" aboard Mrs. Parr's jet quavers very slightly to mimic the small turbulence bumps encountered in flight.
Fight Club features not so much "camera" as "film" abuse, from the subliminal message insertions of Tyler Durden and artificial 'cigarette burn' marks, to when the film appears to jitter right off the spokes during Durden's "you're not your fuckin' khakis" monologue.
Inversely, 28 Weeks Later has a zombie use a rifle with a nightsight attached to it to beat a character to death, seen from the scope's POV.
In REC, the policeman is constantly shoving the camera and telling Pablo to turn it off. At one point, Pablo bashes in an infected's head with the camera. Later, another infected smashes his camera light.
In Cars, one of the little VW Bug bugs flies into the camera and smudges it with dirt.
Subverted in Tim Burton's Charlie and the Chocolate Factory, where it appears that Willy Wonka has walked into the camera, but it's actually the doors to the glass elevator (which is virtually see-through).
In Harry Potter and the Prisoner of Azkaban, the Whomping Willow shakes snow off its branches during the transition from winter to springtime scene, and some splashes onto the screen.
During the climax of Transformers, the fight between the Autobots and Decepticons abuses the camera to the point where it is sometimes nearly impossible to tell what is going on.
The Nutty Professor (1963) ends with the principal cast members walking up to the camera one by one to take a bow, theater-style. Jerry Lewis walks up last, stumbles wildly, and falls onto the camera.
A spoiler reveals that Paranormal Activity would have ended with the possessed heroine beating her husband to death with his beloved camera Quarantine-style, but they didn't have the time or money to figure out a way to do this without sacrificing their only camera.
Hellboy 2: The Golden Army. The first monster battle has monster blood splashing on the camera. It might have 'worked' if the redshirts who had been filming earlier hadn't already been eaten.
Bruno Mattei's Robowar (a shot-by-shot clone of Predator) includes a scene where the titular war machine kills a man who, in close-up, spews blood into the lens of the camera from his mouth.
Inverted at the end of 9, where blood-on-lens violence is averted in favor of a gentle-raindrops-on-lens upbeat ending. Contributes to the concluding Crowning Moment of Heartwarming because the raindrops are shown to be teeming with microscopic life, reborn on a once-dead world, in the final fade-out.
An in-universe example occurs in Happy Gilmore, the viewer is shown home videos from the protagonist's childhood, and footage is shown of his father being struck by a hockey puck while operating the camera, complete with a broken lens.
Crank High Voltage shot the tricky/dangerous parts of the action scenes with relatively cheap High Definition camcorders because if they were damaged during the shoot, it wouldn't cost too much to replace them. They went through 15 of them.
In Fletch Lives, a camera gets knocked askew during a car chase scene.
In Iron Man 2 the cameras that recorded the ill-fated North Korean and Iranian attempts at Iron Man knockoffs get the errant dakka/blood on the lens treatment.
Apollo 13 has Fred Haise slightly puking on the lens after launching. Yummy.
In the first The Lord of the Rings movie, when the (first) bridge they cross collapses and falls, the camera shakes subtly to mimic the seismic effects of a giant rock striking another giant rock.
In Earthquake blood spatters the camera lens when the overloaded elevator plunges down the shaft.
In Twilight: New Moon, CGI werewolves knock over the camera as they charge past it.
The entirety of The Troll Hunter, given that it is shot entirely using a handheld DV In-Universe Camera carried by one of the main characters. Several shots devolve into meaningless shaking, shots take time to focus, and the lens of the first camera cracks its lens when it falls to the ground when a troll eats the cameraman. Several of the next shots are done with a cracked lens until a new camera (and camerawoman) is brought in.
The camera in Chronicle, among other things, is kicked around by bullies, has a drink spilled on its lens, and gets exposed to some mysterious phlebotinum that causes all kinds of interference.
Los Olvidados has Pedro throwing eggs at the camera after being thrown into "Farm School".
Wreck-It Ralph. In-universe, no less. The camera robot in Hero's Duty is used by Ralph to shield himself against one of the Cy-Bugs when it lunges at him. It collides with the camera, which breaks the videoscreen. The sentient robot gets pissed off at Ralph for doing this.
During the car chase scene in the mall in The Blues Brothers some of the musical instruments hit the camera causing it to shake and at the end of the scene a person runs into the camera.
An in-universe example shows up briefly during 44 Minutes, a dramatization of the infamous North Hollywood shootout when one of the bank robbers starts taking potshots at a news helicopter, which wisely gets out of there before any actual damage happens.
In Muppets Most Wanted, Constantine literally smears Vaseline on the camera lens to achieve a romantic effect at one point.