Drupal's page cache is capable of delivering blazing fast response times, but only when the cache is warm. And the reality for most small to mid-sized sites is the page cache is being cleared out far quicker than it's regenerated.
Our old friend Boost is suggested in the comments. We should simply make it standard.
Except where otherwise noted, content on this site is licensed under a Creative Commons Attribution 3.0 Unported License.