Tobacco. 10,000%.
I smoked 3 packs a day for 25 years.
Then when vaping appeared on the scene, I switched to vaping - HEAVY vaping, loads of nicotine (you could buy 100 mg/ml nicotine base by the gallon for a few bucks back when it was still free). For 10 years.
Then finally I quit vaping. It's been 5 years.
I'm finally free from tobacco. And it's entirely thanks to vaping for me. I tried a million times and only vaping finally peeled me off tobacco (and then it took me 10 years to peel myself off vaping, but that was easier).
That's what it took and how long it took me to get off tobacco. I curse the everlasting shit out of the day I took my first drag on a cigarette...