How about LBV1806-20. Nice, quiet little star....150 times the diameter of the Sun and 200 times as massive
4-40 million times brighter, depending on the mood it's in
Or larger still, some of the old Pop III stars....some of them may have been as much a 1000 times as massive as the Sun!! 1 billion times as luminous!!. That's about 22.5 magnitudes brighter than the Sun, meaning the absolute magnitude of one of those stars (when they existed) was around -17, all of the time. In other words they shone constantly about as brightly as what a supernova shines, these days!!.
To put that into perspective, the Earth could orbit one of those stars from nearly 3 light years away and still get about the same amount of light as it does from the Sun