There are more than ten, but here's the first ten that come to mind.

1. A good sermon comes from the Bible. Okay, obviously. Why state the obvious? Because this remains the most important part of preaching and many behind the pulpit fail to do it today. The Bible is not to be used as a launching pad for the preacher to say what he wants to say, as a proof text to support a pre-conceived idea he spawned, nor as a pulpit decoration. The message of the text—the point God was making through the human author—is to be the point of the sermon. To get to this the preacher must ask, "What was the biblical author trying to say?" and when he finds the answer that is the point of the message that should be preached. John MacArthur stands at the front battleline when it comes to preaching straight from the Bible.
2. A good sermon has hammered the preacher all week. When the preacher enters the pulpit as a man who labored over, wept over, was broken by, fueled by, and filled with the joy of the passage all week long, his sermon is real and the people can tell.
3. A good sermon is set on fire by the Holy Spirit. Sometimes the greatest sermon notes from the best orators have fallen like snow on a cold day while mediocre sermon manuscripts from lightweight preachers have turned masses to repentance and spawned revival. How the sermon impacts the people is a work entirely dependent on the Holy Spirit, and the Spirit alone can breathe life into the preacher's sermon and make it fly. In no way am I discouraging hard study but there have been times when I studied 25 hours for a sermon and it came out like a wingless airplane, while at other times I've been asked to preach five minutes before I was to start, and with no notes or preparation God enabled me to preach a 45 minute message which God seemed to use more than every sermon I preached in the last twelve months.
4. A good sermon is contemporary. To some, this may seem like a contradiction to the first point, but it's not. A contemporary sermon does not mean the text has in any way been shielded or diluted. A contemporary sermon simply means that the sermon is packaged in such a way that people of today can immediately understand, relate to, and know how to respond to the message. Two preachers can preach on God's holiness and both deliver the exact truth with complete accuracy and yet one audience walks out with questions bouncing around in their head while the other walks out convicted to the bone but rejoicing that Christ is their holiness. What made the difference? The first preacher was accurate and ancient. The second preacher was accurate and contemporary. Preaching an ancient text does not require preaching with an ancient style. A preacher may be accurate, but if he has failed to connect with his audience and to show them the relevance of God's timeless Word, he is doing injustice to God's people and to the Word of God. His congregation would be better off staying home and reading commentaries, since after all, that's all he is, an accurate, precise, boring, droner who cares more for his studies than the people. But a good preacher knows his sheep just as Jesus does (John 10), and he knows their struggles, their pains, and their needs, and he speaks to them in a way that makes them laugh, weep, smile, and even get angry.
5. A good sermon is Christ-centered. I learned in seminary that when breaking down any text, it is my responsibility to "principiize" the text, that is, turn it into principles. Now this is very helpful for crafting an outline and communicating the passage practically and clearly. But it's only halfway. The preacher must show how that text fits into the bigger theme of the redemptive theme of Scripture and how it points to Christ. Every text ultimately finds its fulfillment in Jesus. If I preach three keys for holy living, many believers may go home trying hard to apply those three keys as if God's acceptance level will increase with their performance. And an unbeliever may walk out thinking: "So that's what it means to be a Christian. Obey rules and be a better person." If the sermon I preach would be readily accepted in a Jewish synagogue, Islamic mosque, or Hindu temple, we've got a problem. Christ-centered preaching includes two things: First, it shows how the text fits into the big theme of redemptive history. For example, although Joseph's flight from Potiphar's wife serves as an excellent lesson in fleeing sexual sin, the redemptive theme behind this story is how God uses Joseph's faithfulness to get him into prison, to raise him up as second ruler of Egypt, to preserve his family, to preserve the line of Judah through whom Christ will come. Second, the Christ-centered sermon shows the listener that the only way he can possibly apply the message is if He's redeemed by Jesus and empowered by Jesus. He must see that Jesus not only demonstrated perfect faithfulness to God but died for all the times the believer failed to obey Him. Bryan Chapell and Tim Keller model this approach.
6. A good sermon shows love and sensitivity for the lost. I don't mean we should refuse to talk about sin, repentance, and hell. Nor do I mean we should ignore people's eternal needs and just pacify the felt ones. If Jesus talked about these things, how could we not? But as you prepare your message ask yourself: What are the most typical unbeliever objections to these principles? The first time I did this it drastically effected how I packaged my message. The core message and truth was left untouched, but the way I said things changed and I suddenly realized how often I arrogantly expect unbelievers to just jump on board with all my big "ology" words that only members of the Christian tribal dialect would ever hope to get. Chances are, at least a few unbelievers will be there every Sunday morning, and we need to be thinking about them in our preparation. Tim Keller is a champion of this.
7. A good sermon relates to the audience. This is similar to point #4 but is so important it warrants its own paragraph. Notice how good preachers almost always begin by relating to their audience through natural humor, a personal story, or even sharing a struggle he encountered this last week. Another key time for doing this is when telling a personal story to illustrate something in the text. This gives your flock a chance to get to know you a little better. When a preacher is open and personal, he emulates Paul's example all through 2 Corinthians. Paul never feared being transparent about his deepest struggles with his own churches. When a preacher is afraid to be transparent it may signal a heart of pride. I'm not saying spill your dirty laundry for all the congregation. Do that and you're no longer leading. But don't be afraid to let people know you bleed when you get cut, sneeze when you inhale pepper, and yell when you stub your toe. After all, your family knows the real you and if you try to don the "spiritual" coat for Sunday morning your family will pick up on the hypocrisy and some day imitate or resent it. Could this be the answer to the classic PK problems? Well, that's another article... John Ortberg is an expert in relating to his audience. He uses personal illustrations to give his audience a dose of humor which is another gift of communication God gave to humanity and should be used intentionally! Here's a great example from one of his sermons (I have not listened to the entire sermon so I can only speak for the humorous anecdote): "Someone sits in front of a nutritional disaster—a plate full of salt, fat, sugar and grease, fried in oil and covered in butter, and what do they pray? 'Dear God, bless this food to the nourishment of our bodies so that we can do Your will.' Is that some kind of a joke? That would take a miracle! At that moment, God’s will would be for you to push back from the table and give the food to the dog, but dogs matter to God too! So, His will is probably for you to give it to the cat."
8. A good sermon is delivered with excellent communication. Taking a speech class, reading books on good speaking, video-taping his messages and watching them are some of the best investments a preacher can make. No matter how accurate he is (and accuracy matters!) if the preacher is not interesting, people won't enjoy listening to him. What good does it do to be accurate if your audience is asleep? And if a preacher is boring, what does his example teach his audience about the message of God's Word? A preacher must do all he can to communicate it to be clear and interesting. During my early seminary days, John MacArthur came in and talked to us budding preachers about saying things in a way that "shocks" our audience, to help keep their attention. Mark Driscoll understands shock value and has milked this technique for all its worth. Illustrations, a pointed introduction and conclusion, quotes, hand gestures, how far apart your feet are, your facial expressions, your clothing, the pitch and tone of your voice, the speed of your speaking, where you look, the timing and frequency of your pause—details like these make the difference between a poor communicator and an excellent one. Perhaps no preacher was a better communicator outside of Scripture than the 19th century Charles Haddon Spurgeon. What many don't realize is that this man was so animated in the pulpit that some Christians accused him of disrespect to God and compared him to the actors in the theatre (a big slam in Spurgeon's day).
9. A good sermon is God-fueled. The preacher invites his audience into the passage to see the heart of God and His passion for His glory as the text slowly unfolds. The preacher is so consumed with God's character displayed in the text that he can't help but tremble at the awesome holiness of His majesty. If this is real it will never be something the preacher does by affectation. It will come out naturally. He will smell like God, speak as one who stands in God's presence, and bring the people into the holy of holies to be undone by the presence of God until their hearts respond in shouts of praise and worship. John Piper has exemplified this like no man I've ever heard. We must be careful lest undue time spend on point 4 (a good sermon is contemporary) leaves the sermon so familiar and so comfortable that the presence of God feels like a foreign object.
10. A good sermon builds community. The traditional American approach to Christianity for years focused on one's personal faith at the expense of the value of community with other believers. Individualism most certainly had a hand in this. But today, many preachers are recapturing the heart of community by letting their sermons paint a picture of what happens when an entire community of people grow and change together. Andy Stanley models this feature with excellence. The emergent church emphasizes community often at the expense of doctrine, but some are still holding the tension faithfully such as Tim Keller and Mark Driscoll to name a few.