Alcohol in moderation is not addictive -- I nibbled a little bit for roughly 40 years without getting addicted to it.
Tobacco is another matter altogether -- even just ONE cigarette can be addictive due to all the harmful chemicals tobacco companies put into their products. And I've heard its the hardest kind of addiction to overcome.
Don't know about illegal drugs -- never tried them.
coffee of course is as addictive as is heroine. A single snort can get you hooked for life.
Yet most people will violently object to that fact (which is of course a clear sign of their addiction, pot smokers also deny the addictive nature of their addiction).