The better one is Nintendo ds lite because it has bigger screens than Nintendo ds, smaller and more compact, easy to take out the stylus and does not hurt your eyes as much as Nintendo ds. Though, very sorry to say, sony psp is a million times better than both of these.
The Nintendo DS Lite is lighter and smaller than its original counterpart. It also has a bigger display and has a longer lasting battery. Finally, it is equipped with four brightness levels, a feature that the Nintendo DS does not have.