Really nice article running down the major caching plugins, including some ones I have never heard of. I'm a fan of W3 Total Cache myself, having tried about four of them on various sites. I like the CDN integration, the fact that it doesn't change your URLs, and that it combines file and database caching. Not to mention it is actively maintained.
Most interesting are the options that turn out to be worse that no caching at all.
CSS-Tricks does nearly 2.5 million pageviews a month and can run OK without caching, it's just much faster and surge-protected with it on.
Update (404 link removed 2016/07/02)