Heroin: The entire world felt covered in a warm golden glow, and time seemed to slow down. Everything felt peaceful and relaxed. No concerns about anything, just total relaxation, along with a warm rush throughout the entire body, similar to alcohol.
LSD: The entire world was colorful and different. Closing eyes lead to many color patterns always changing. Total physical pleasure, constant shivering which felt indescribably good, physical contact like cuddling felt even more intense and warm.
Meth: Just a total relaxation and sense of purpose when staying still, when physically active, tremendous amounts of energy and physical precision. Made music sound mind-blowing.
MDA/MDMA/Ketamine Combo: Was so overpowering that I nodded off for a bit. Total relaxation and every task was immensely amplified. Connection with other people felt like talking to the closest family member, lover, and friend, all in one.
Many more, just top four experiences.
EDIT:
Special note for cannabis in a spiritual context. Total sense of purpose and creative ideas that I've never had when not high. Immense euphoria from sunsets, music, and socializing.