My main camera is a Canon 5D Mark III which is a professional quality full-frame camera. This camera has excellent light sensitivity and can capture good images even in low light conditions. Since it is a full-frame camera, it means that even with some cropping, most images will have enough pixel density for you to be able to print large canvases of the image and get excellent high resolution quality.
I have an assortment of fast lenses that I switch between depending on what is going on at the event--if I need to be far away from something that is going on but still want to get detail shots, I use a 70-200mm telephoto lens. If I'm near enough to the action and/or want a wide angle view, I default to my 24-70mm. If the light conditions are very dark and the use of a flash is not a good choice, I switch to my prime 50mm 1.2. This is also a good lens for getting the type of pictures where a very specific part of the frame is in sharp focus but the background is blurred.
I prefer to make use of available light but also have powerful flashes and other light crafting equipment and use them when needed.