I write the Dominion Strategy
blog as well as the Twilight Strategy
I enjoy learning new games, but I derive the most joy out of exploring a game very deeply. I think a game is most fun when you are good at it and playing with others who are also good at it.
I place a very high premium on simple and elegant rules.
I dislike games that involve constructing elaborate plans only to see them dashed for reasons beyond your control. I also dislike downtime in games, especially games where you need to do a lot of planning but can't do any of it until it's your turn.
My two favorite games are Twilight Struggle and Dominion. I do not foresee any game ever displacing Twilight Struggle as my favorite, and I do not foresee any game ever displacing Dominion as my most-played (about 4,000).