My 1995 bmw 5 series wont start! it acknowledges the key in the ignition, but when your turn the key nothing happens. it makes no attempt to start engine whatsoever.

Had the same problem, My issue had to do with the door locks? I guess the door locks are tied into the ignition for security purpose. I had to get out and close the door put the key in the drivers door, lock it and than unlock it (make sure all the door lock knobs go down and up) than it started right up.
Strange I know but it has to do with some type of security issue?