This is hard to compare, weed is actually the worst I think, although usually its not a killer.
You see, cigarettes we see to do more damage, but take note, smokers usually smoke at least once or twice a day, some smoke like a pack or two a day even.
I don't assume people that smoke weed can get THAT much and smoke it every single day, since weed has nearly twice the chemicals and harmful effects as cigarettes do.
As for alcohol, same thing, 1 drink isn't dangerous, 10 drinks are, so this topic is very general.
So are we comparing the lasting effects overtime or just 1 of each?
Since 1 joint > 1 cigarette > 1 drink of alcohol
Weed is the worst?
Get the fuck off my name. The real Anarki smokes cannabis almost daily. Dumb as mother fucking kid. Stop being so ignorant to what chemicals are harmful and what are not. THC has killed no one. Alcohol and the chemicals in cigarettes NOT including tobacco kill hundreds of people daily.