Attack on Titan proved in its very first episode that it is an anime capable of producing amazing visuals, and it all started when the Colossal Titan appeared and blew a hole in Wall Maria. As its name suggests, the Colossal Titan is massive, but that isn't what makes it powerful.
Eren Yeager is the current holder of the Attack Titan and he has shown just how formidable it can be in a fight. As far as abilities are concerned, the Attack Titan is capable of seeing the memories of its past and future holders, which can come in very handy.
The War Hammer Titan was the last of the Nine Titans to appear, and its debut was truly exciting. Unlike the other Nine Titans, the holder of the War Hammer can control their titan from afar thanks to a cable made of titan flesh which allows the shifter to hide in a crystalized case underground.
At the end of Attack on Titan's first season, fans learned that the walls protecting humanity were actually made from thousands of slightly smaller colossal titans. These titans are mindless, but together, they are capable of destroying all of humanity.
The full extent of the Founding Titan's power can only be activated by someone who possesses royal blood, but when this condition is met, it is by far the strongest titan in the world. With its scream, the Founding Titan can force Eldians to transform into titans, and it can alter the memories of Eldians as well.