Do not forget the customer
Customers pay for your fun job, they know the problem area much better than you do and they share an interest with you to make a good program. Do not forget them!
In an ideal world customers should be as entwined in the project as the developers, project managers, architects... For some reason there is usually a need to fight with them a bit to make them a part of the project. Try telling them that the project costs so many millions and that without the know how for a comparatively small cost the project might fail.
The project needs the customer. Their involvement brings so many vital benefits and very few hazards. You minimize the risk that you will discover that you misunderstood what the system was supposed to do after a few months, you solve problem areas much quicker and you have nicer coffee breaks.
The customer on the other hand will hopefully start to understand the fabric of your work and he will be reassured to see that you are not only taking coffee breaks all of the time. At least not without him.