You really do need to think about what it is that you bring to the table. Do you feel that you are one of the best in your field? Do you find that you are called on to do the things others can't? Do you generally get things done better / faster than others? If you answer yes to these questions than you need to ask for more than the national average for your position. Companies, especially large ones, are not in the habit of giving away something for nothing. They must see merit in you. They must also believe that at your present salary there is the potential for another company to offer you more. Remember you will get one kick at the can. Don't axpect them to ask you this question again any time soon. What is the worst thing that will happen if you ask for more than they are willing to pay? You can be sure that they already know what your worth. They simply want to find out if you do.