I have recently been playing more solo board games. In fact, I have even brought games with the purpose of playing them solo. For the most part, they have been good. However, I do enjoy solo gaming, and one of the key features of this is a win/loss condition.
Solo activities, on the other hand, I find boring quickly. Some games I have tried recently (such as La Granja and Feast for Odin) were definitely more on the activity side. I have no interest in constantly trying to better my score, instead wanting a clear goal and some antagonistic AI to fight against.
On the other hand, games that give an AI to play against, good choices and clear win/loss conditions have been very fun to play. In particular, games such as Adventuria. I also like a game that you can set-up and pack-up in a short time by yourself, as it highlights one of the strengths of solo play (low downtime and faster pace, normally).