http://en.wikipedia.org/wiki/Joseph_DunfordMostly a staff weenie, but Gen Mattis was pleased with his handling of 5th Marines in the invasion of Iraq.
" He next served in the 1st Marine Division where he was assigned to command the 5th Marine Regiment, then as the division's chief of staff and assistant commander. During this time, he served 22 months in Iraq.[8] During his command of RCT-5 in the 2003 invasion of Iraq, he earned the nickname "Fighting Joe" under James Mattis.[9]"
His ribbons aren't anything to brag about, they are all "I was there" stuff, not even an expert shooter badge.
On the other hand, that might not be a bad thing since CJCS IS essentially a political and administrative job and that is where his skills seem to lie.