It won't let me just recommend Brave New World, the last expansion. Game was alright before BNW, but BNW filled it out a lot.

My favorite space 4X so far, especially recommended for multiplayer. I played a lot of hotseat SE4 when it was new. Lots of depth.

Not my personal favorite space 4X, but its very solid and perhaps the best AI in the genre

So, so good.

I played EU3 so much and this is that game with subtle but much needed improvements

Grand Strategy Medieval Life Sim

Tropico games are all kinda the same, but 4 is the one to play. Don't be lured into 5 with its bells and whistles, 4 has plenty to keep you entertained

4X Fantasy (a theme this year?) that builds upon what Endless Space did right while being much more interesting than ES. AI not too shabby either.

4X Fantasy with a unique goal and storyline that keeps you from getting too cozy in your small realm

4X Fantasy with a focus on wars and battles.