Simple, Reliable & Correct, Fast (in that order)

"Simple, correct, fast: in that order" (coined by Drew DeValut) is one of my favorite programming phrases. It says so much in so few words.
Make sure that you read the original article, it's not long.

I usually like to expand it with the word "reliable", because it makes it more clear that you need simplicity to get (and maintain) reliability and correctness.

If you approach the reliability and correctness through simplicity, you'll also get more important characteristics:

On the other hand, with more complex/intertwined solutions, even if you manage to temporary achieve those characteristics, it will be extremely hard (or impossible) to maintain them in the long term.