I always go at least 5mph over in zones where the limit is 40mph+, and keep with traffic on highways. In residential zones though I go the speed limit and get quite pissed when roostery highschoolers start tailgating me for it, and slow down 10-15mph below the limit and keep them from passing. Irresponsible, but don't like the idea of a 5 year old getting smacked because a kid had to show off in front of his girlfriend. Tailgating is really the only thing that pisses me off, and have gotten into stuff with because I frequently flip people off for doing it and actively try to piss them off.