When I was a junior in high school, I bet my track coach that I could do 100. I lost, but I did do 77 full ROM dips at 142 lbs BW. Now I'm 40 lbs heavier and my right arm goes numb after a set of dips, but I'm going to do a set tomorrow just to see what I can do.
edit - I'm 41 and weigh 180 and I did 30 full range of motion dips this morning.