It also depends on your monitor, i have a 22inch acer (1680*1050) which insists on stretching every image to the edges of the screen no matter what the res/aspect ratio. This cant be fixed by software/driver updates, its just what i get for buying a budget monitor
Personally i quite like the slight blur effect you get from stretching the image to fit the screen, it smooths out those nasty jaggy edges, its like free antialiasing
