well, the very traditional recipe for pie crust is 3-2-1; 3 parts flour, 2 parts shortening, 1 part water, which is pretty much what i use, although i eyeball the water.
as andy says, there are a lot of recipes, and many use a much lower ratio of fat. since you've brought the subject up, i'd guess you've reached the point where you need to strike a balance between taste & health. good luck!
personally, i don't use much fat these days except olive oil and non-cholesterol margarine for toast. and virtually no cholesterol fats. but i draw the line at pie crust, mincemeat, and christmas pudding. so there's about a 4 - 6 week period at the end of the year where i wouldn't want to go get a blood check.