I use NextD mostly to play games that I usually play on my cell phone, on the big screen. The platform is the best I've seen for playing high quality mobile games. The other alternative would be to use "mirroring" with something like Apple TV but that usually doesn't convert over well from a controller perspective and also the throughput and integrity of the picture is compromised.
I mostly play Sim City and sometimes Minesweeper. Every so often I play Angry Birds.