I haven't tried many drugs in my life. The most intense i did was a legal substance which is said to be just like marijuana, only stronger and involves closed-eye hallucinations.
It was great and everything: Every time i closed my eyes there were these incredibly complex patterns (really, you can't understand how complex and precise they were) and it was constantly zooming out of it, revealing that those were only a small part of something bigger, and it kept going on. Music was strange, if i focused on it, i was able to slow it down somehow.
Anyway, it was great, but didn't get even close to my LDs, which aren't even that long for me yet (i'm kind of a beginner).
I didn't try LSD or anything like that, but from my personal experience, Lucid Dreaming is the best. And i hope i'll be able to get the maximum out of it.