Well for me discipline is the most important. Because even if you have the most wonderful plan on how to better your life, without disciplining yourself to work on those plans, they will remain just plans and your life would be worse off for that.
Discipline is like the fuel you put into a car to make it move. Our lives is that car, without the fuel of discipline there'd be no movement. Because discipline always leads to action and action is the main thing we need to change our lives.
There are many geniuses that have achieved only the average or nothing at all because they lacked the discipline to work on their lofty plans or put their wonderful talents to good use, and there are many average people that have achieve superlative things because they were disciplined enough to work on their average plans.
How has having self control, or not having self control, impacted your life?
Well let's say I'm the genius in my previous comment who has achieved little because of lack of discipline. You know, lofty plans, wonderful dreams. Of course I work at my goals daily, but I'm still far from reaching my full potential. But little by little I'm learning self-discipline.
Knowing you're far from your full potential is good, it means you know improvement is required and that helps you determine what things to do to find that improvement. Apply discipline and you'll be good to go.