I recently picked up the game Frozen Synapse and it is pretty fun (assuming you like this sort of game).
In short it is a turn based game of tactics. The turns are simultaneous so you and your opponent (computer or human) give orders to your troops and then the game runs things forward about 10 seconds and battle resolves itself. Rinse and repeat.
When I say “tactics” that is exactly what this is. Very heavy on the tactics. Pretty much all it is. Maps are procedurally generated so you rarely see the same map twice (I found in single player if you restart a map you get a different map although if you restart enough you may see the same one again so perhaps in single player it is pulling from a pool of maps…does make it harder to “learn” a map though).
Graphically the game is simple (also a very small download for a modern game…only a few hundred megs). No super flashy graphics but what is there is very clean and crisp. The game makers also made sure there is a lot of polish to the game. What they do they do very well with no hiccups, great multiplayer options and so on. Additionally, you can give orders to the enemy troops in the planning phase and then run a simulation of what will happen. These orders in no way affect what those troops will really do but you can guess and try various approaches before you commit.
I have not played multiplayer yet but from what I read people are enjoying it.
Last, the game has an interesting (and I think clever) sales model. When you buy the game you get two licenses and can gift the other license to someone else. I already gave my second license away (there was only one Doper on my list of “want this game” so I gave it to him).
If others here have it might be fun to give multiplayer a try.
ETA: The music in the game is actually pretty good too.
ETA2: Here is a video of someone playing the game which shows how it all works pretty well. WTF Is... - Frozen Synapse ? - YouTube