15%! Without a doubt. But, I also feel that if you get exceptional service and the waiter or waitress was not bothering you alot, except when you felt was appropriate, then by all means, do leave a larger tip!. Waiters and waitresses are only paid have the minimum wage. Having been a waitress in the past, I do know that if you are a good one? You will recieve not only a good tip, but I have also had customers tell a boss, what a wonderful waitress I was to them. I always went out of my way to make sure you had the condiments, that you would likely need to go with your meal, so as to not only cut down on me bother you, but also gave me more time to clean my tables, as most places I worked at, I was usually the only waitress, because I could waitress. There really is an art to waitressing, but sadly I don't see a lot of good ones, like I was trained many years ago, for our resturants in our family. However, I do try to remember that not all resturants, really know how to train their waiters or waitresses, on a right or wrong way to do things, as there is a right and wrong way to do them.