I'm going to throw out a hypothesis that a good board game requires you to make decisions that you are going to regret later.
If you don't regret the decision later, then either everything can play out from the beginning with you knowing all the events that will happen, or there are some choices that are so optimal or so sub-optimal that you can continue to just follow the same path time and time again to succeed.
This is why I am still enjoying Race for the Galaxy because with the economic decisions it places on the players, you have to make meaningful choices from the very first hand. Okay, admittedly sometimes you can futz around for the first few rounds trying to figure out how to win, but really once everyone playing gets to a familiar level with the cards available if you aren't moving on your strategy by the second or third round you've lost.
I'm trying to figure out what it is that hits the sweet spot because I don't want to be limited to just one or two games every week. Okay, I've got several games on my shelf and can rotate through them with ease. But I'm always hungry for the next game, or a different feel. For example, I was introduced to Power Grid this past weekend and it reminded me how much I enjoyed auctioning mechanics, I like that sort of social back and forth with another player at the table to change the nature of the game.
The only trick is finding a game that scratches that itch without too much of the extraneous stuff that interferes with the enjoyment of the game.