Which star is the brightest

+6
+1
0
-1
-6

-6 is. The larger the number the faintest!

I believe there have been several scales used to represent Star brightness. The most common has the equal to our own sun as a +1, getting brighter as number increases.
There is a good video about this on youtube, Sixty-symbols.

The brighter the object appears, the lower the value of its magnitude, therefore -6 is the brightest.

Magnitude -6. The brightest star in the Northen hemisphere, Sirius, in Canis Major known as the "Dog Star" is only -1.6

The lower the value, the brighter the star.
So -1 is brighter than +1. And -3 is brighter than -1.

-6 I think because +one are dimmer. +6 is the dimmest we can see and the sun to us is -27 so -6

-6

Apparent magnitude of the Sun < -26