The most addictive game that I've played is this cooking game on iOS called: Cooking Royale. It's a game where you actually have to cook the food in real time. It's timed and really gets your fingers moving. I don't buy apps much, but I ended up buying the full game for this one.
I like Vector, it's parkour inspired gameplay is just too good to put down. Not to mention, the graphics are real good and the game ran rather smoothly.
I played Clash of Clans and it was very addicting. The downside of the game is that it needs an internet connection. The game is very time consuming but it's very very fun to play. You can chat to people all over the world and make your base looking all pretty. Also if you're into action, you can raid other bases and steal their loots which is honestly my favorite part of the game.
I agree that Clash of Clans is horribly addictive. I had to delete it because it was taking so much time off my hands and I kept thinking about it all day. It's very easy to get hooked on that game.