Actually, I avoid paracetemol (as it's called on this side of the pond) under all circumstances.
If it were brought out today it would never get approval by the FDA/MHRA for over-the-counter use because it's way too easy to overdose and destroy your renal system and it has some pretty dire synergistic effects for people taking a whole range of other common medicines.
Aspirin is much safer for headaches, despite it being a bit hard on the stomach if you overdo it. Ibuprofen's okay but I find that better for muscular pain. YMMV of course.