I recently made the switch from shared hosting to a VPS over at Slicehost. The reason is for administrative control and performance, but after setting up my usual Apache + PHP + MySQL server and hosting a single Drupal site, the performance of the site was terrible! The server was eating up 300MB of RAM and using up a good chunk of swap too- and that was with just 1 person accessing the test site. Ouch.

I decided to try out Nginx (after doing quite a bit of research comparing Apache to Nginx and Lighttpd) and was surprised at how easy it was to setup. Slicehost has some very good articles to get you started, so I won't go over that, but if you're installing Drupal, there are some really good forums for creating virtual hosts, and setting up Nginxs implementation of mod_rewrite (for clean URLs).

Nginx: 1, Apache 0.