Tylenol is much safer than any NSAID including asprin. You have to really, really try to hurt your liver with acetaminophen. What's happening with prescription analgesic combinations is not limited to acetaminophen -- people are abusing them, diverting them, and taking them in every fashion except as prescribed. Taken as prescribed, there is almost no chance of hepatotoxicity with these medications.
For every legit acetaminophen hepatotoxiciy case I've seen, there have been 100 complications from NSAIDS -- namely peptic ulcers and kidney failure -- but sometimes life threatening bleeding complications following surgical procedures due to platelet inactivation. Every medication has a good and bad effect. Aspirin and Ibuprofen can have seriously deleterious side effects, even when taken in the proper dosages.