KISS principle
A KISS is what the user want... :)
KISS - acronym for "Keep It Simple, Stupid". We have no time to learn complex things, so we want a KISS software, a KISS web page
This is my favorite principle. It is so simple :)
"everything should be made as simple as possible, but no simpler." Albert Einstein
A very good implementation of this principle is jQuery, a javascript library - fast and concise