The biggest buck I've ever personally seen was a reportedly (I can't verify that myself) 180 class buck that I saw from 140 yards away last November in Illinois.

My guide was hanging a stand a 1/4 mile away or so and saw the buck heading in my direction. I saw it come out of a strip of woods and accross a field. Through my rangefinder (that's how I know how far away it was) all I could see was what looked like someone's ribcage stuck on a deer's head!

He didn't stick around long enough but went into another strip of woods and (presumably) around behind me.