I WOULD filter past all stopped cars. It's not my fault that they can't
Seriously though, my only real filtering opportunities are on stretches of road that also have a bike lane so I go right up to the front of the line. The only time I don't is when I'm coming up to a stretch with no bike lane after the intersection and there is a bus or truck that's first in line or near the front. I will let them get on their way as it's harder for them to pass me after the intersection. The cars can suffer - it's a lot easier for them to move slightly over than it is for a bus.
Besides, buses are our friends.
== Traffic lights, the great equalizer ==