I mostly obey the laws, and I do it because it fits my self image as a law-abiding citizen, and allows me to feel smugly superior to other people . However we always have to balance safety, standards of behaviour, practicality, and comfort in everything we do, so, like everybody, I veer a bit away from absolute adherence to the law in a few areas where it is safe to do so and it would be impractical or very uncomfortable (or even dangerous) to adhere strictly.

The best example of this is stop signs. There is no good reason for a cyclist to stop at a deserted, uncontested stop sign, except the fear of a cop seeing you, or a rigid adherence to the rules, and it is a huge cumulative waste of time and effort to do it all the time. Cops generally tolerate rolling stops by cars and bikes, so I have developed the habit of making the same rolling stop on a bike that I would in a car. Convenience trumps the law here.

If I'm approaching a red light after midnight and there is no traffic in sight, and it's a sketchy part of town, I might actually consider it safer to keep going than to obey the law and stop, and give a mugger a chance to jump me. So safety trumps the law here.

If I'm approaching a stop sign and a car is beside me, I notice they often make a complete stop, because they figure the cyclist won't, and they want to show him up. So I always fully stop too, and point at their car and say "Very good job! Usually drivers don't stop completely". Or sometimes I say "thanks for the demo!"