I guess the question needs further qualification.
There are many engineering disciplines such as mechanical, aerospace, civil, electrical, computer, chemical, metallurgical, nuclear, . . . .
and within each discpline there are numerous specialties, e.g. in mechanical, one can specialize in structures, thermodynamics, thermal-hydraulics, fluids (fluid dynamics), corrosion, . . . .
What are the criteria - number of journal articles, inventions, most important development in the field (over what period - this year, the last # years)?
http://www.nae.edu/nae/awardscom.nsf?OpenDatabase awards (primarily or exclusively US).