I saw a great story on the Fifth Estate yesterday (the Canadian version of 60 minutes). It said that the success rate for the Patriot Missile was zero. Reasons given:
- the military lied about intercepts of SCUDS as part of the propaganda
- the Patriot system was designed to intercept airplanes, not SCUDs which are much faster

Quite shocking. Here is more info.
http://www.radix.net/~jcturner/patriot.html