In my opinion the only really bad fat that needs to be completely eliminated is the partially hydrogenated stuff like margarine. They are unnatural and cause such a laundry list of problems I would need a book to tell you them all. If you eat natural saturated fats like butter and animal fat without going crazy on them you will be fine. Just read the labels on prepackaged stuff you buy and watch out for anything that has a lot of partially hydrogenated oils in it.
I realize I sound like a broken record with recommending this book but read Protein Power Lifeplan by Drs Mary and Michael Eades and you will wind up being a Rhodes Scholar on what is and is not healthy for you overall and why.