If you will be shooting towards the sun do not use any filter, period.
If you will be shooting with your back to the sun in order to get the warm low angle lighting on a skyline, you still won't find any filters particularily useful.
If you are shooting at an angle not far from 45 degrees into a skyline made of glass-curtain highrise buildings with the rising sun reflecting in the glass, you might find a polarizer useful for adjusting the brightness of the reflections.