How Much Better Are Aftermarket CPU Coolers Than Intel’s Stock Coolers?

Building a gaming PC is an expensive proposition, even on the “value” side of things—we’re talking about at lest $500 for a new machine. Penny-pinchers often forego unnecessary extras. And since most CPUs come with a cooler right in the box, why bother with a big bulky aftermarket cooler, especially if you’re not going to overclock anything?