When I volunteer at the local co-op, I'll reach for the Park PW-4 before any of the others. I like the way the head offers a couple of angles for mounting the spindle flats. At home, I use a Park HCW-6, which has a 15 mm side for pedals - Or, I just use a regular 15mm open end wrench. depending on which is closest at hand.
I have to say that I very seldom encounter a pedal that requires a lot of force to break free. Technique is important: mount the wrench on the spindle flats so that it forms an acute angle to the crank. This give you a lot of mechanical advantage.