The closest thing to a 1-hit wonder I ever smoked (probably more like a 3-hit wonder) was WW5. As far as I know, it was a Williams Wonder/NL #5 cross. Wow! My entire body went numb. Wish I had some right now!
I buy this entirely.
The original Super Sativa Seed Club description of M31 Williams Wonder from the late 1980s said "two people couldn't finish a joint". You'd think that's just ad copy exaggeration, but from personal experience, it true.
First time I tried this, one normal joint couchlocked myself, another hardcore stoner, and made a third novice white out and pass out on the ground. In fairness to us, all of us were accustomed to smoking low potency sativa-heavy schwagg. Not only was this stuff probably 2-3x as potent as what we were used to, it was also qualitatively different too.
More recently, I smoked three normal puffs from a normal joint (so maybe 1/5 of a joint), and I was DONE. I "could" have smoked more, but I just didn't want any more and had to stub it out. One bong hit of this would have definitely been enough.
In general, these pure indicas can be total "wreckers"; they're good for medical use, but they're definitely not for everyone. Some people just pass out after smoking stuff like this. . .good for insomnia, I guess! Also, in my experience, you build tolerance to these heavy indicas pretty fast.