I have and still do occasionally (no kids).
Cannabis, pills/mdma, coke, speed, ketamine a few times.
Ketamine for me was horrible.
Immediately passed out on the floor and vomited, remember nothing until the next morning. That for me was scary so I wouldn't take it again.
Never had a particularly bad experience with any of the others, though. Most vomiting/crying/loss of memory is related to alcohol rather than anything illegal.
I've only ever used recreationally, though, and not particularly regularly. Average over the last ten years of once every couple of months I suppose. Drink only at weekends, hold down a professional job.
Not really sure about legalisation. I do find it terribly hypocritical when people take a blanket view of drugs=bad booze=ok. Quite often they are people who have no first hand experience and, as someone mentioned previously, lump things like pills and heroin together.