3 Sightings Come To Mind For Me.
1) When I was in middle school, my class went on the obliagatory trip to the library. The libararain there was about 5-3 or 5-4, average weight or so black female around 50 who was humungous. In her bra, they hung down to her waist, and even then it looked like their were two heads on top of her stomach. They even looked heavy. They were probably J Cup +.
2) I was headed to the gym earlier this year and saw this lady about 5-6 or 5-7, late 30's, well dressed with some humungous implants. I didn't recoginze her, but she had to be making a living with those things. She was proably in the I-K cup range.
3) One lady that I actually see on a regular basis is this poor lady who hangs out at the local library with her husband. Late 40's, skinny legs and arms, but huge breasts. I know a girl who's an H cup, and this lady is clearly larger than that.
I work at a gym, so I see some big boobs here and there, but nothing beats the night clubs in the L.A. area if you want to see some big breasts.