I don't have much experience with turn-based games overall but I bought the XCOM collection during the Steam winter sale. I fired up XCOM: Enemy Unknown and so far I think it is really well done. I like that they do a bit extra for immersion (e.g., when you research something new you actually talk to a researcher vs just clicking a menu) and they add a nice amount of flavor while keeping gameplay central. Really enjoying it so far and I appreciate that the missions are fairly short, making it a good game to hop in for a mission or two then hop out.