I set the record among my friends for getting my buddy to O'Hare international airport from Skokie IL. 21 minutes. The speed limits I broke were 75 in a 35 on side streets, and 90 in a 65 on the highway. I had to get him to the airport in under 30 minutes to get him on his plane.

Outside of that, I usually drive 5mph over the speed limit.

Edit: speaking of leadfoots, I remember a guy on a motorcycle attempting to set a world record for most expensive speed ticket. I think he did 165mph on LSD (Lake Shore Drive). The dude had to stop and wait about two minutes for the police to catch up.