I've been playing x beyond the frontier, great space exploration game, there is a story but i don't really care about it.
Just "flying" through space with that soundtrack is such a relaxing thing, is great to play while a watch a cartoon or youtube video, or maybe just listen to a podcast.
I also got x2 and x3 with that one, once i'm finished with this one i might go for the sequels
The bioshock games (1, 2 and infinity) are all really good fps games with a good story and the best part of it, is really easy to buy all of them for dirty cheap on steam when they are on sale