I don't if I should call it addictive, but Terraria needs lots of hours to be played.

Warzone 2100. I've been installing and uninstalling that one for weeks now. It's only barely less addictive than crack.

Ditto. I think I've had Assassin's Creed installed ever since I got this current lappie of mine over two years ago. Still actually haven't gotten around to playing the game, while I've installed, completed, and removed again quite a few others.

As a young gamer (I started to play games full time too late) its hard to mention name of games which I got addicted to.

There are two games that I got addicted to.
1. [PROTOTYPE]
I liked its gta+monsters mashup.
There were days when I played it non-stop for 16 to 18 hours per day.
I played it back to back 7 times.
Then my exams came and I had to uninstall it.

2. Risk of Rain
I got it as a gift from a nice person on facebook.
I played it's DRM- Free version for countless hours.
Then I installed it on steam.
It became only game which is still installed and which I play on steam.
Even after 1000+ hours of gameplay I still play it for 4- 6 hours a day.

Sometimes I even play it in my dreams.
I wish they could introduce new levels or a dlc or an expansion for it so that its players could get some more hours un kill.

Disciples 2. Heroes of Might and Magic 3. And if the upcoming 1.3 patch is as good as it looks like it might be, probably Worlds of Magic, as well.

This...and I've tracked the problem down to the respawn system and my lack of a flying piggy bank (Money Trough). I don't have a teleporter system yet, and even having many locations with beds doesn't really help. I keep wanting to explore a little further before I go back to a piggy bank location to deposit my gold, and next thing I know it's been two hours....

I should remove Dota 2 so I could focus on my backlog more - but that's a half-lie, nevertheless.

Should just tackle down on backlog harder than I am at the moment.

Edited, I sometimes suck at English.

FreeCell.

ALIEN S0X 3000: GOTY Gold Edition: The Quickening.
===

semi-serious answer: i did sell my PSX when i was in school, because my grades were falling and i wasn't getting enough sleep. however i got myself addicted to pokeymans soon after. pokeymans took up less time though, because i refused to spend 50 bucks on an overpriced power adapter, and relied on rechargeable batteries.

Same here, specially about the snapping part, that why I love to play Hunter, if its a bad draw or good draw, game is over very quickly:)

My other game would be league of legends as I love trying all different champions.

Diablo II, Titan Quest, Divine Divinity.. I still feel the urge to install and play the hell out of them again but since I have too many other games I would like to play, I'll resist.. I'll try..

There are two games I can think of that somewhat fit this description.

The first one is The Sims. That was back in the days - I installed it, added cosmetic mods, created characters, wasted a whole day on not really doing anything, before I realized I was essentially just playing with a virtual dollhouse. It was addictive, but also very dull and meaningless, and for the first time I came close to understanding what some people mean when they say videogames are a waste of time. After that day I uninstalled it and never touched it again - not because I thought it was bad, but because I sensed that it was bad for me.

The other one is Might & Magic VI, but that counts double because I actually uninstalled it twice for that reason. First time was during my studies when I thought it got too distracting and took away too much of my time, second time was over a decade later. I install it, play around with it for a bit, two days later I realize it's taking away all of my time and I'm totally obsessed with it. And I don't even like it that much, it's just pointless grinding most of the time, made worse by the need to constantly travel back to town in order to rest, so it takes ages to clear out a dungeon. This game is pure poison, so I said good riddance!

I guess I was lucky though that all in all I lost less than a week to my addiction. The rest of my lifetime so far has been dedicated to all those harmless videogames that I could always stop playing, if only I wanted to! So thankfully, I don't have a problem with addiction anymore, no, I don't. ;)

Diablo *

I had to uninstall it and throw it in the bin to prevent myself re-installing it yet again.

Its charm is that it was so easy to get into and thus tempt one with just a quick game that... didn't end until many hours later.

I've still got Diablo 2, but it's less addictive because it's a tougher game and so a little intimidating if you get your build horribly wrong. Diablo's hook was mindless fun.

* GOG, this is one game you must never, ever bring here!

I had a lot of fun with warzone 2100 myself earlier in the year but by the time of the first terrain change (from brown->green) where you had to defend a base or something, I was done with it. The difficulty and the suicidal unit AI started to get on my nerves. I resolved to play Earth 2150 instead, in the event that I ever wanted o play something like warzone 2100 again.