* Apparent Brightness: If you're asking about the star that appears the brightest to our eyes, then the answer is Sirius, also known as the Dog Star. It's a binary star system located in the constellation Canis Major.
* Intrinsic Brightness: If you're asking about the star that emits the most light, then the answer is R136a1. It's a massive blue supergiant located in the Tarantula Nebula in the Large Magellanic Cloud. It's about 300 times more massive than our Sun and shines with the brilliance of 8.7 million Suns.
So, it depends on what you're looking for! Sirius is the brightest star we can see from Earth, but R136a1 is the star that actually emits the most light.
