Right hand.
Some people use a long breaker bar, rest it on the frame and bump the starter to loosen it. Make sure to pull the coil wire if you use this method.
Another person I know could not get his loose no matter what he did; he ended up slicing pieces out of the flange on the bolt. Then it spun right off.
I had to do the same thing to one of the cam bolts on my 3.0.