I don't know about ministry, but I heard a song or two, and they sound nothing like NIN. Anyways, NIN is a great band, even if you don't "get it". For anyone intrested in them, the good ones are the fragile and the downward spiral. Just take a few extra listens and consider what they are doing besides pop melodies, pay attention to the important stuff like the story line (yes, it is a concept album), the experimental guitarism (played by adrian belew, who is from king crimson and the talking heads), and the electronicaish layering used throughout.
EDIT: sorry this was off topic. It is just one of my pet peeves when people diss a band without really listening to them.