I find that pathos is typically the most effective, seconded by logos, with ethos in last place.
Explanation:
Many people use sob stories and the like to great effect, while, in many cases, those who use ethos are shut down by others who are certain in their belief that they know better. Logos is in between of this. Honestly, it depends on who you are talking too. Just remember, many humans are ruled by their emotional centers, and not their logical ones.
