I know ldl cholesterol is known as the "bad" artery clogging cholesterol, but are there healthy levels that are good for you?

Less than 100 mg/dL: Is considered optimal. For someone with diabetes or cardiovascular disease, a level of under 70 is considered better. With ldl, it seems that the lower it is the better.

Depends on Particles: Ldl can be estimated by cholesterol (ldl-c) or measured by particle number (apob or NMR ldl-p). However, ldl-c and ldl-p do not equally predict cardiovascular risk. When ldl-c and ldl-p values disagree (due to cholesterol variability per particle) cvd risk tracks with LDL particle number, not ldl-c values. Ideal ldl-p values are <1000 nmol/l for high risk patients and <1300 nmol for everyone else.

LDL Not Cholesterol: 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. Nmr particle test <$100.