Once again I have a biased opinion I would go Alpine. Eclipse also rates very high and not as expensive as Alpine. It all depends on how good of an ear you have and how picky you are with sound.
If you are running your front speakers in your doors (like most people) you can look into headunits with digital time correction which allows a delay in the speakers which are further away from your ear so that it seems that they arrived at the same time.
Are you drawing power from the headunit or are you going directly to an amp? If you are going directly to an amp, you really dont need a built in amplifier. But you may need more pre-amp outputs.
It all depends on what your needs are