Love this as a priority, and not just as a coder, but as anyone involved in building software. I've noticed an extremely high correlation with how enjoyable a code base is to work on, and how easily I get into The Zone on that project. Hopefully I don't need to elaborate on the correlation between The Zone and developing a kick ass product in record time.
As for the meaning of enjoyable, well... hire great developers, listen to them when they speak, and make having a great, well designed, low code debt code base a priority whenever possible.