Depends on your goals.
A bare minimum should always be 15%.
If I were cutting, I would go for 25-35%, unless I was aiming for ketosis.
If I was bulking, I might go for something like 15-25%, but everybody has their own preferences there. I know some people who have had success with a low carb bulk and others who have had success with a low fat bulk. All in all, the minimum is 15% for hormonal reasons.
i usually do about 20%
I voted 20-25% because that's usually what I end up at by the end of the day, without really trying.