My 2004 Pontiac Grand Prix shakes when i hit my brakes could you please help me

Ok I just got new breaks on the front do you still think i need rotors

examine the front tires carefully, or have them rotated front to back. a separating tire will vibrate. After that I would simply replace the rotors. Rotors are very inexpensive and easy to install yourself so that's a quick and inexpensive way of ruling them out. If the vibration is still there I would suspect a bad axle shaft. If you change axle shafts replace the wheel bearings at the same time with good quality North American made parts.

also check your bushings mine went and now car runs great no more shake