This is an animated gif of a dog hitting a man in the face with his paw. The man stares at the dog until the dog finally reacts by slapping him with his paw.
This is an animated gif of Will Smith with a shocked expression on his face. I'm not entirely sure what episode/scene this is from; all I know is that this is from the hit TV show "The Fresh Prince of Bell Air", which is the show that catapulted Will Smith to fame. This is a great reaction gif for whenever you're wanting to express how shocked you are.
This is animated gif of the Dalai Lama laughing before putting on a pair of sunglasses. I'm not completely sure, but I think he's at a press conference or something. The Dalai Lama is a "high lama" in the Gelug / Yellow Hat branch of Tibetan Buddhism. Tenzin Gyatso is the current Dalai Lama.
This is an animated gif of drug kingpin Marlo from The Wire. In this scene, Marlo and his crew are having a meeting after being arrested. Outraged that his second-in-command didn't tell him that Omar had been talking about him, Marlo shouts "My name is my name".
This is an animated gif of Avon Barksdale wagging / waving his finger at Lt. Daniels. This scene is from the hit show: The Wire. In the scene, Daniels and his crew were trying to follow Barksdale across Baltimore. However, Avon quickly figured out that he was being followed and decided to cheekily drive past Daniels and wag his finger at him.
This is an animated gif of Spiderman giving a good old fashioned facepalm. In case you didn't already know, a "facepalm" is when somebody puts their hand over their face. Usually, this is a result of somebody else saying/doing something that was stupid.
This is an animated gif of a cartoon seal shouting gay / gaaaaaayyy. According to KnowYourMeme, this meme is called "Homophobic Seal". It's basically used to dismiss what somebody has said or done (I think we've all had that one friend that says "gay" after something has been said). Anyway, this gif was made by Reddit user SmellingYellow.
This is yet another animated gif of Michael Scott from The Office. In this scene, Michael is dressed in hockey gear and decides to tackle a man as he's skating along the ice rink. Michael tackles the guy and crushes him against the side before celebrating.
This one is an animated gif of Michael Scott from The Office saying "No! God! No, God, please no! No! No! Noooooooooo!" This is a great reaction gif to use whenever you hear news that you don't like. This is from The Office (US version), which is a comedy television show. Michael Scott is played by actor Steve Carell.
Related: Michael Scott - This is the worst.
This is an animated gif of Jim Carrey from Dumb and Dumber (movie). Dumb and Dumber was released in 1994 (has it really been that long?). Anyway, in this scene, Carrey is disgusted about something. It's been a while since I saw the movie, so I can't exactly remember what he's reacting to. If I had to guess, I'd say it would have something to do with the dead budgie being sold to the blind kid.
This is an animated gif of Jim Carrey. I think that this scene is from the movie: Liar Liar. In this scene, he gives off a fake laugh. His expression then turns to annoyance as he turns around to walk away. This particular gif reminds me of how I react whenever somebody makes a funny joke at my expense.
This is an animated gif from "Tim and Eric Awesome Show, Great Job!" In this video, a black and white couple are playing some sort of quiz game. After the white guy gets a question wrong, the black guy presses the buzzer. However, instead of letting it go, he continues to hold it. For a few seconds, he is smiling. However, this smile of his slowly fades and he begins to manically stare at the camera. My guess is that he either hates the other couple (they're extremely annoying in the video) or he hates the game.
This is an animated gif of comedian Jerry Seinfield putting his hands up into the air (as if to say "I've had enough") before getting up from his seat. This one is a great reaction gif for whenever somebody tells you something that you really didn't want to hear. This is from the hit TV show Seinfield.
Edit: As somebody in the comments section pointed out, this scene is actually from Curb Your Enthusiasm, which is an American comedy show.
Here's an excellent animated gif of Red Foreman from the hit TV show "That 70s Show". Red stars as Eric Foreman's dad and is particularly known as being a hard-ass. In this particular reaction gif, Red pulls down his newspaper and is extremely angry about something. A great one to use whenever you hear of something that both shocks and angers you at the same time.
This is an animated gif of Dawson from Dawson's Creek wagging his finger, as if to say "Oh no you didn't!" Obviously, this is a great reaction gif for whenever you disapprove of what somebody has done/said online. I'm not sure what TV show this is from exactly. All I know is that the actor player Dawson on Dawson's creek a while back.
This is an animated gif of a small boy shouting / mouthing the words "That's racist!". The gif has been edited to include a number of offensive racial stereotypes about black people. From what I can see; the kid is spinning a basketball on his finger while eating watermelon. Also, a bucket of KFC is floating in the background.
This is an animated gif of Dr. Cox banging his head against a table. Obviously, this would be a great reaction gif for whenever you feel frustrated or annoyed about something. Dr. Cox is a character in the hit TV show Scrubs, which was a comedy drama show about several medical staff at Sacred Heart teaching hospital.
This is animated gif of The Joker clapping. The Joker was played by Heath Ledger and this particular scene is from the Batman movie: The Dark Knight, in which The Joker is in prison. Heath Ledger, the actor, tragically died before the movie hit cinemas. Obviously, this is a great reaction gif if you want to show some sarcastic clapping.