Out of things that I've actually been "addicted" to...
1) Hydrocodone
2) OxyContin
3) Alcohol
4) Suboxone
5) Cocaine
6) Marijuana
Addicted is in quotations because I don't even consider Marijuana being an addiction. Cocaine is purely a mental addiction as well, AFAIK. I smoked pot every single day of my life from the time I was 15 until I was about 22. Got pneumonia and literally could not smoke it for a few weeks, and afterward I figured why bother? I didn't enjoy it anymore and it was costing me (at least, what I considered at the time) a fortune.
Cocaine I only did regularly for about 2 years but it was likewise very easy to stop. I was kind of smart about it... I was still young and trying to be conscious of how much my life was spiraling out of control, and when I hit a certain point (8 ball a day) I said that's enough of that and put it to rest. Still did it every once in a blue moon after that, and still will on occasion... but since that time I've never done it more than 1-3 times a year.
Suboxone was my most recent addiction, capping a decade long spree of opiate use and abuse. I tried to get on it intermittently over the course of a couple years, finally stuck with it about 6 months ago and quit nearly a week and a half ago. I never took a lot of it (usually 1-2mg/day) and tapered down over the course of a couple weeks. The withdrawals were nothing AT ALL like the horror stories I've heard. They were seriously mild or at times nonexistent, and I have no lingering depression or unbearable cravings a scant 10 days (or so... not sure exactly) into this. I think if you use this stuff right, or in other words - not at all like most doctors who prescribe it deem "the right way" (e.g.: starting out at a ridiculous 16mg/day) - it's super easy to come off and amazingly effective at providing a bridge back to normalcy.
Alcohol was very tough, though moreso mentally than anything else. I did get the shakes for nearly a month after I stopped drinking, but the overwhelming feeling of total worthlessness and wanting to kill myself constantly was what really sucked. If I wasn't upping my opiate addiction to insane levels at the same exact time, I never would have got through this so perhaps it should rate even higher. This was my very first drug-of-choice and I was a hardcore drinker from the time I first picked up a bottle. I'd actually say being addicted to opiates was a better reality for me than being an alcoholic. I did way more stupid, insanely dangerous things... made more incredibly bad decisions... ruined more relationships, hurt more feelings, and did more psychological damage to myself being a drunk than with all my other insane substance abuse COMBINED. I'm still in complete amazement that I never got a DWI or killed anyone driving like a maniac. It's been long enough that I can have a beer or shot and not wig out, in fact ever since I quit I've never really even gotten to the point of being DRUNK, drunk... though if it was up to me, I wouldn't drink at all. Most times I just will because I'm in some kinda social situation where I feel like an asshole not having a beer in my hand.
OxyContin and Hydrocodone may as well go together, they're essentially the same thing/same withdrawal. I put Hydro above Oxy because I never went through a full Oxy detox (1-2 days of that hell at most, then back on or on to Subs). Hydrocodone I only went through the horror because I didn't realize that Suboxone existed at the time, I had a BS drug possession charge, was getting piss tested as part of a pre-trial counseling/probation thing and they were about to throw me in county lockup if I came back with one more failed test. Once I beat that (literally one week later, haha) it was right back to the pills! -- anyway, THERE IS NOTHING WORSE IN THIS WORLD. For those who have experienced it, you know exactly what it is. For those who haven't, it's indescribable. I think actual physical torture may be a better fate since you at least know you'll probably die at some point. Every muscle in your body aches, your mouth tastes like someone shit in it constantly, you wish you could rip your skin off your body from the cold sweats and temperature fluctuations, your limbs can't stop moving, if they do you want to rip them off too, there's a sickening feeling of death and hopelessness at the core of your body and mind that eats you up every second of every day for over a week - and once that's gone? You still want to do nothing but get high. The anguish your mind and body goes through with opiate withdrawals really changes you as a person, it's incredibly tough to get back to being happy about anything after the only thing that has made you happy for so long has been those fantastic little pills. Like I said, I did this shit for about a decade - started out taking 1 or 2 Vics a day and really didn't increase or feel any WDs for a good half of those years. After that? It gets really bad, really quick. You have no idea it's even sneaking up on you. I think I've squashed those cravings a good bit and it'll get easier as time goes on... but I am ABSOLUTELY POSITIVE I will do these drugs again at some point, like an asshole. That feeling is just too good. If I won the lottery, I would do this shit every day of my life and die in 15 years happy as a pig in shit. If somebody told me I could ONLY do opiates or ONLY fuck and get my dick sucked for the rest of my life, I'd have a really hard time choosing option #2. I probably wouldn't. For those that have no experience and can't understand why this stuff is so bad - think about that. This is a drug that's bond is so powerful it can short circuit the most essential basic human instinct to reproduce and survive. If it can do that, think about what else it can do!
Sorry for the INCREDIBLY long post, I tend to get very wordy... although hopefully it adds some perspective for people in similar circumstances. I promise that will be my last ever complete history of drug abuse posted on here, LOL.
PS - Til this day the only thing I have not successfully kicked is TOBACCO so perhaps that should be #1? I've never stopped long enough (no more than a day, LOL) to even get withdrawals from it, so I didn't add it into my list...