Most drugs at the moment can be found that are very high quality. Cocaine, benzos, mdma and heroin really stand out as drugs that are easy to find in high potency.
Ketamine is widely available but mostly poor quality in comparison to the Indian ketamine of yesteryear. Meth the same. Both these drugs aren't incredibly difficult to synth apparently yet both lack quality in my experience.
Is Acid any good at the moment?
Acid is the best it's ever been.