Which is the healthy cholesterol: ldl or hdl?

HDL: Hdl is commonly referred to as the "good" cholesterol and LDL is the "bad" cholesterol.

Neither: Cholesterol is neither good or bad. The idea of good and bad cholesterol come from our use of cholesterol as an common way of estimating the quantity of "good" (HDL) and "bad" (ldl) lipoprotein particles that carry cholesterol in the blood. Research has established that it is the number of LDL and HDL particles, not the cholesterol inside the particle, that is the best measure of chd risk.

Neither >> Particles: Cholesterol, a fat made by all our cells & ~30% of fat molecules of all our cell membranes, has never been the correct issue. It was promoted because (as a fat within all lipoprotein particles) it was cheaper to measure & if very high (esp. Fasting) tended to correlate with high LDL particle concentrations. In the later 1970's lipoprotein measurements cost $5, 000/sample now NMR particle test <$100.