WEBBY! Nice topic. Let me share something. My clients have great rankings too. Yes there is always room for improvement, but how much? Get a REAL Google Analytics report to uncover opportunity.
In addition, look at your incoming traffic. I told my clients that I have to stop being so dependent on Google because a change in their algorithm can cause a dip in traffic. I started changing focus from link building to relationship building. Some call it community building, some build their Fabebook/Twitter account. I help individuals and try getting them to grow so I can get my clients repeat business. That's the key on my end, repeat business.