Alcohol. Hangovers suck.
Although probably the worst "comedown" I've had was on shrooms. I shroomed all night and by 4 A.M. I was so mentally exhausted all I wanted to do was sleep. I ended up lying in my bed till 6:30 (felt like days instead of hours) watching my walls move waiting for it to stop.
However, if I could do it all over again, I would in a heartbeat. Gotta love boomers.
Oh, and the comedown off E kinda sucks. Took adderall once...comedown sucked on that too.
Thank nature that weed doesn't have a comedown. Or much of one anyway. Nothing a weed nap wont take care of
Edit: +rep twoLOUD for your siggy. I think I gave you your second bar.