Brining is preferred, but if you can find quality "air-chilled" whole chickens like from Bell & Evans, you can get away without the brine. My small local market one block away carries Bell & Evans chicken. Perdue might also offer air-chilled. Most commercial chickens (Tyson, Gold'n'Plump) are "water-chilled" in a big bath of bleach and other undesirable stuff. Those need some help, by brining to correct the water-chilling bath, and flavor. If you care about that, check your chicken brand online, or ask the butcher (these days, there are very few butchers who know any of this stuff, so don't automatically believe your chain grocery meat guy who comes out from the back).