Biggest time sink for me was an MMO called Asheron's Call 2, first and only MMO I had ever subscribed to. At first I used to roleplay a lot and only play casually, but then I got caught in the crafting/resource grinding threadmill and kept playing every free minute I got. They had this crafting site, where all crafters were listed with their skill, and I was like on place 13 on my server and I wanted to make it in the top10, so that meant harvesting materials for hours on end to improve the skill. In the end I had to cancel it because it got out of hand, so I'm back to singleplayer games now, it's much more chilled out.
