I have stopped playing Skyrim long time ago too, even before I got to meet the good dragon whose name I can't remember anymore. At one point, the gameplay just stopped being interesting, and the only things driving me forward were the story and the atmosphere (curiosity about the world was the first thing to fade away, yes, it's beautiful, but composed of relatively few elements in various visual forms, which is not enough for me). and then I got a quest that was on the other side of the map, which meant shitload of time before the story progressed again (because I forbid myself from fast travelling), so the interest in story faded too. now the only thing remaining is the atmosphere of being in that world, which is the only reason why I occasionally play it for half an hour or so. It turned into an ambient relax tool for me.
on the other hand, I can't stop playing Dishonored, the story lost its intrigue after the third complete playthrough, but now I keep coming back to play the missions by themselves, trying to be as much "super amazing stealth cool death machine Chuck Norris ninja" as I can, having awesome moments and adrenaline rushes like I had in no other game for ages. Beats even those I had from AC1 and 2. I'm also starting to think about trying to do completely nonlethal (nobody ever killed) playthrough, maybe together with complete ghost one, but that doesn't seem like what I'd enjoy right now, just curious if I could pull it off.
so yes, this situation happens to me sometimes, but it's very rarely, because novelty in games is very important for me, and once I don't feel it anymore, most of the appeal of the game is gone, I feel like I know the game even if I didn't finish the story or saw all the locations - I'm more of a game mechanics explorer than asset explorer.
Before, this (the addiction, kind of) happened to me with GalCiv II. Before that, Braid. And both Portals.