How can you forget something like the Adafruit Huzzah[1]? It is so nice with the ESP8266. We use it in home-assistant (http://home-assistant.io) for things like this temperature sensor[2].
[1] https://www.adafruit.com/products/2471
[2] https://home-assistant.io/blog/2015/10/11/measure-temperature-with-esp8266-and-report-to-mqtt/