MYTHEME_preprocess_node is the best solution as it is a theme adjustement. However, when you're using a default Drupal theme, then instead of hacking core, use hook_node_view_alter(&build) inside a custom module.
This blog was started as I had the need, as a starting Drupal 7 developer, to avoid losing time searching the internet and projects I've worked on over and over again to find code snippets and examples helping me achieving my goals. Over time, I hope this blog can help other open source developers improve their game.