When I was younger - ahem - I had this series of books called Angelique with 22 volumes.
And I think I've read the whole thing minimum 8 times.
The printing was very tiny and the pages were all yellow and aged, but I loved it.
I would put my feet up under me in the recliner and have a cup of coffee next to me and start reading - one after the other.
The story about this young girl growing up in France, when Ludvig the 14th was king, was told so vividly, that it sucked me in for days.
Of course with a game it's different.
But some just have this "Je n'est-ce pas" over them, that keeps you coming back - over and over.
For me it's games like Broken Sword, Syberia 1 and the new Perry Rhodan.