There's no such thing as good LSD and bad LSD. The psychological effects are so profound in their unpredictability and incongruence from one trip to the next that people have forever been sucked in by the idea that there are different kinds of LSD.
By definition, Acid is the drug LSD-25 (a copy of the 25th synthesis of compounds analagous to d-lysergic acid diethylamide) - in other words, it's either LSD or it's not. The only variation is in the strength (by way of active quantity ingested) and nothing else. There is no such thing as different kinds of acid.
Oh, the good times I've had.