WEIGHING in... (ha ha, I kill me!)
I think this is something that is very individualized and you have to find what works for you, like rockymountainsavvy stated. It may take some trial and error.
Most days I personally have about 50-25-25 or 50-20-30 (carb-fat-protein). Some days (maybe a quarter to a third of the time) I am 60-20-20. I think must metabolize carbs very well; if I go below 50%, I am hungry and cranky. I have read all the articles on how carbs convert to sugar and are therefore "evil", but I have lost weight steadily and had bloodwork done last month with triglycerides at 43 (supposed to be below 150), so I don't think this ratio is hurting or hindering me, unless there is some aspect I'm not aware of. I try to make sure they are whole grains and fruits.
I really don't have a taste for high fat foods so some days I have to think about how to get my good fats up there (usually nuts or Larabars). I have been working on weight training so I am trying to be more conscious of the protein lately.
You can find anything on the internet or in a book or journal to support any position, but at the end of the day, you have to do what works for you and your body, or you won't stick it out.
And now that you don't have to be perfect, you can be good.