Quizzical Tilt

It is common in all forms of animation, as well as in Real Life, for a character to tilt his head sideways in confusion. In anime this is often accompanied by a "...", while in western animation it is more often accompanied by a "...huh?". A raised eyebrow is common in every genre.

Common in Animal Reaction Shots, especially with dogs (although animals who behave like dogs may do it too), accompanied by a Quizzical (or Disapproving) Whimper.

Related to Head-Tiltingly Kinky and Fascinating Eyebrow.

Examples of Quizzical Tilt include:

Advertising

The old RCA Victor ad had a dog with its head tilted quizzically as it listened to a phonograph record play, with the title "His Master's Voice".
- The famous trademark image comes from a painting by English artist Francis Barraud, A.R.A. and titled His Master's Voice, which provides this page's image. The original title of the painting was "His Late Master's Voice" (and this phrase appears on many of the original RCA Victor labels), but the concept was considered too depressing for most of the public's tastes, and certainly for an image used as a means to put the consumer in the mood to buy. It was acquired from the artist in 1899 by the newly-formed Gramophone Company.
- The logo remains in use today by the British music store HMV, whose name is an acronym of the slogan.

Anime and Manga

Luffy from One Piece is incredibly fond of this, tilting his head whenever something even mildly puzzling occurs. Don't know which direction is south?

"Hm...." [ quizzical head tilt ] "That way's warm, so it's south!"

Those creepy-cute tree spirits (kodama) from Princess Mononoke are very much this.
Osaka of Azumanga Daioh does this.
Nia in Tengen Toppa Gurren Lagann does this when she sees Lagann in a garbage heap.
In Durarara!! Celty and Shizuo do a simultaneous version, which A) goes to show their Like Brother and Sister bond, and B) is absolutely adorable.
Used by Yuki in The Melancholy of Haruhi Suzumiya when Haruhi tells to use her "magic powers" to zap Mikuru during the production of their student film. Considering how Yuki is the epitome of the Emotionless Girl, this is her equivalent of a stunned gasp (particularly how she does have reality-warping powers of her own).
Naruto from his own show Naruto does slight head tilts early on in the show when he didn't understand a concept or wasn't familiar with something (which, being Naruto, happened quite a bit). An example is when he first heard of the Chuunin Exams from Konohamaru.

Fan Works

Used several times in Kyon: Big Damn Hero:
- Tsuruya when Kyon received a greatcoat as a gift from Mikuru, and realized it's the same coat she saw him wearing some weeks ago.
- Mikuru when Haruhi is explaining her plan for a type 2 Tenchi Solution with Kyon and the girls in the brigade.
Observed as an intriguing, if foreign, gesture that humans often do in the Mass Effect fic, First Contact. The fact that it's almost ubiquitous among both dogs and humans is just one of many things that drives home the fascinating dynamic humanity has with dogs and cats (to the point of major coevolution that continues to this day).

Film

Wild Wild West: A "blink and you'll miss it" Shout-Out occurred when "Bloodbath" McGrath was lying on the ground and a dog came up and did the "His Master's Voice" bit while looking at McGrath's ear trumpet.
Starman had Jeff Bridges tilt his head quizzically for most of the movie—but that's because he was a non-human life form from outer space learning about the human experience as he went along, so everything was new and confusing to him.
The Fifth Element: Leeloo gives a tilt of her head to the Major before breaking out of her unbreakable container and taking from him the key to opening it.
Detective Hoffman does this towards Strahm in the glass box in Saw V
In Halloween Michael Myers does this when examining some of his victims.
Jason Voorhees does this twice in Friday the 13 th series. First in Part VI when he sees an Auto Erotica going on and in Part VIII when he sees a billboard for a hockey league which features a hockey mask similar to his.
In The Mask, Stanley's dog Milo does this the first time Stanley turns into the title character.
Star Wars: Return of the Jedi - the Ewok whom Princess Leia befriends headtilts at her when she tries to talk to him.
- The child actor (Warwick Davis, in fact) who played the Ewok stated that he purposefully modeled this behavior from his own pet pooch.
Ripley gives a "Like hell you will!" variation in Aliens just before going berzerk in the alien nest.

Live Action TV

Spock made considerable use of this, as well as the Fascinating Eyebrow (and sometimes both at once).
- Data quizzically tilted his head every ten seconds or so.
There's an episode of Will and Grace where Jack says 'reluctant pivot, inquisitive head tilt' as response to Will.
In Supernatural, this is Castiel's typical reaction to Dean (or others) not making sense from his angelic perspective. I think he's patented his version, actually.
Teal'c from Stargate SG-1 typically paired it with a Fascinating Eyebrow when something about Earth culture confused him in the early seasons.
A very common gesture of The Man From Atlantis.
Cameron does this. A lot.
Illyria on 'Angel' seems to be doing this the entire damn time.
Kurt from Glee is good at these, but they tend to be somewhat less inquisitive and somewhat more interrogative. As in "we-have-ways-of-making-you-talk" interrogative. Especially when the frosty eyebrow lift and serial killer Death Glare get in on the act.

Professional Wrestling

The Rock has done this. Though it's usually accompanied with getting your ass kicked.
- He would also say it during interviews or when one of his promos were interrupted, usually followed by...

Rock: ...and just who in the blue hell are you?

Kane did this back when he wore a mask and didn't have a voice, probably borrowed from Michael Myers of Halloween.

Video Games

Mass Effect 2 includes a particularly good scene where Joker does this after EDI cracks a hilarious, albeit very poorly timed, joke.
Emperor Palpatine hilariously does this when accessing Imperial security panels in Lego Star Wars.
In Kingdom Hearts coded, Data-Sora, Mickey, Donald, Goofy, and Jiminy all perform one together as Data-Riku explains the nature of his existence.
Emil Castagnier of Tales of Symphonia: Dawn of the New World tends to do this a lot as well.

Web Original

Doki does this in There She Is when Nabi tries to explain that interspecies relationships don't work.
Cute Overload calls this the "baroo", after the sound dogs (supposedly) make along with it.
a disproportionate amount of Slenderman-related media portrays him as having his head habitually tilted to one side.
When Linkara joined The Nostalgia Critic to review Superman IV this was his reaction to Supes' "repair The Great Wall of China vision".

Nostalgia Critic: Does Superman have wall repairing ability?
Linkara: <quizzical tilt> ...not in any comic I've read

The standard problem-solving method used by The Simple Dog in Hyperbole and a Half. It doesn't work.
On the vlog Vlog Brothers, Hank composes a song from weird noises sent in by nerdfighters to get his brother's dog to tilt quizically. It works

Western Animation

The Simpsons, "Sweet and Sour Marge":

Marge: Don't you have any sense of corporate responsibility?
Garth Motherloving: [tilts head, confused puppy-dog whimpers]
Marge: Hey! [claps twice, and Garth snaps back to attention]

Kitty from South Park has done this.
In The Thief and the Cobbler, there's a scene where Tak and Princess Yum Yum do this to each other for several seconds.