Looking at the tables, it appears the benefit to filing separately reaches its peak opportunity if the spouses' incomes are equal or nearly equal. There may be other factors that optimize filing separately. As the difference in the incomes becomes greater, i.e, wife with zero income, filing jointly seems to be best.
I have done my own for almost 40 years, surviving a 30 page return one year and audit questions the last 3 years. Not that I don't trust CPA's, but doing it myself gives me a sense of what records are important. Turbo Tax will do the calcs and let you know if joint or separate is the best deal, and it will figure alternative minimum tax if applicable. AMT is a pain to figure by hand.
Conan - I think you can save some money on your taxes if you will poke your eyes out, but you should consult a CPA before you try it.