For me that depends on where the road is. If it is in downtown where there's trafic is heavy, I got pinch between two car from both lanes when I was at the far left side, the car in the left lane was hugging his right side and the car in the right lane was offcenter to his left. Drivers sometime don't notice me at the left side of the right lane although I am wearing a bright green cyclist jacket. I'm currently waiting for my arrival of my MS tail light so I can use it during daytime. Otherwise on less crowded street, I do take the left side of the right lane if I knew that the intersection I'm approaching is known for cars making right turns, but generally I hug the right side far back from the crosswalk to give car space to turn right.

I never take the center of the lane since that one time where the car behind me got smacked by the car behind him who was too busy texting or something else. That car behind was pushed foward enough to have bump me if he was right behind me. Worst case, I might have been pushed into the intersection of on comming cars.