I’ve tried a fair few and for me, top is ValetPro Advanced Neutral Snow Foam, closely followed by Bilt Hamber Auto Foam. The latter being excellent vfm. Both gives foams of a thinner consistency (that can be adjusted via the lance), than some (such as Meguiars Hyper Wash) which are more like shaving foam consistency, but ime, better to have a slightly thinner foam as it clings to soften and encapsulate dirt, then runs of the car taking the grime with it. Some very thick foams can just stay on the car looking impressive but actually doing little other than just softening the dirt. Both VP and BH are very effective pre wash foams.