The standard Intel coolers with the Core 2 and Core i7 CPU's are perfectly adequate if you don't intend to overclock. They're also pretty quiet too.

Even with some modest overclocking, they're probably fine.

Don't be taken in by people telling you that you absolutely MUST have a $50+ third party cooler even when not overclocking.

However, you can not go without a heatsink and fan altogether.