How do I respectfully quit my job?

I find my job to be an insult to my intelligence. The flowery job description was nothing but fluff. I am perpetually bored, and when I do work, it's only to keep me busy. I worked hard to get my Electrical Engineering degree from a highly distinguished university. Yet, I could have done this job out of junior high. Needless to say, I am bitter. How do I quit respectfully? No one at work has any idea how I feel though because I lie to them about how much I love my job (so I do not risk getting fired). Please advise.