It depends on you, everyone has his own taste I suggest you watch some videos about different games then you can choose!
Good luck with finding a good game that you like. the best game ever for me was Crossfire but the CF forum died here and I don't play Crossfire anymore.
Member - 12 June 2016 Premium Member - 14 August 2016 News Force Sports News - 17 September 2016 Premium Seller - 23 September 2016
Thought of some more. SPORE is a pretty fun one, but it's singleplayer. You get to evolve a creature and have it go through stages, I enjoyed it a lot. Terraria is also extremely great, and a single playthrough can take 300+ hours. Has good replayability and is even better with a friend.