Ask YC: nginx or apache for PHP?

Since I did not find authoritative information elsewhere about which one is more preferred in production environments, I thought I'd ask here.

Based on your experience would you go with nginx (+fastcgi) or apache to run a high traffic website that is written using PHP?

It would also benefit the community if someone could post information about any HOWTO/tutorial resources describing the best ways to configure apache/nginx/php for production web servers.