After almost two years and more than 2000 games, I think it's time to complain...
This game is the most interesting board game I have ever played. The major appeal, after so many games, is... actually hard to quantify. The biggest part may be the near-infinite possibility of setups. Consider that you may not encounter a five-card combo once in your life time. Seeing how cards come to work together is really fun. Maybe some other satisfaction comes from proper management? As a experienced player with familiar cards (no, not the one you buy with potion) sometimes the fun comes from buying things at the right time, to out manage your opponent. Maybe, in a small portion of the game, the satisfaction comes from control. The way you mess up your opponent's deck and consolidate your own is just really enjoyable.
However, the more serious effort you put into the game, after some time, at least to me, makes the game more painful. There is only a single problem: luck. Somehow the luck in Dominion behaves in a very different way comparing to the only other board game I have played for a comparable time: bridge. In bridge, luck is certainly very important. But for reasons I don't understand, I never feel as disgusted when I lost a bridge game/tournament, due to my bad luck. In Dominion, watching your opponent use his turn 1 witch/tactician kill you with his good draw from turn 3 to 6, or when both of you did the same thing, but you didn't draw your cards until it's too late, is just unbearable for me. Probably it's due to the fact that in bridge, the luck factor at least will not spit directly at your face as sometimes how it just happens in a dominion game? For me, when I am not in a good mood, the bad draw is just mocking at me on how pointless you are to study the probabilities and expectations of different choices. Double jack is a good strategy? How can it be better than a single Jack if you draw them together in your first 3 shuffle?