Like many here, I often perform the 'Idaho Stop' at T-intersections (left turn at red light after giving way). I also do the rolling stop at pedestrian crossings (roll though at about 5kph when there's nobody on the road or about to step onto it). I do it basically because unlike a car a bike cannot crush or kill someone at 5kph - there is neither the weight nor the torque. Also, I don't ride with headphones so I'm generally more aware of my surroundings than a motorist, who has fewer aural cues with the radio on and the engine running.
I also hop onto the pavement (at 5kph or so again) for short distances if I need to get to a bike path coming off of it, or if someone is parked in the bike lane (illegally) in peak hour and I need to get around them quickly without merging into traffic. I do this because of flaws in the bike path/lane system, and because it's victimless.
I don't blow lights at speed. That tends to be the habit of certain brakeless riders too lazy/unskilled to simply skid stop and start again. Not all fixed gear riders mind you. Just the crap ones.
There is one red turn arrow that I ignore. Either the sensor does not pick up bikes, or the time to change is too long.
I also pop lot's of wheelies because they're fun
Aside from those, the only other one is riding between stationary cars at traffic lights because I can.
I'm sure none of these are against the law though.