The ESP8266 [0] is, in my mind, one of the most interesting things in the microcontroller world right now. It's cheap, small, easy to use, and connects to WiFi.
If you go into real computers, the C.H.I.P.[1] is quite an interesting device. It's $9, which is price competitive with the ATMega644 chip (in single quantities), has WiFi, Bluetooth, and runs Linux. It's also got lots of GPIO, like the Raspberry Pi, so it can be used in places where a microcontroller might normally be used.
I'm sure there are others, but these are the two that are on my radar at the moment.
I'm linking to the SparkFun ESP8266 breakout [0] because I found this to be so much easier to get my bearings with than the raw chips/breakouts I'd gotten from Alibaba. Granted, I got my hands on them very early and they were still reverse engineering the documentation on them, but using this dev board has saved me many hours. It's also quite inexpensive for one or two if you're just trying to play around.
Oh yeah, there's no doubt that you'd need something like this to get started. I figured I'd like to the Wikipedia article because there are so many things being built with this chip that it's hard to point to any one of them and say "this is it". It's really about the ESP8266 itself, what companies like SparkFun are building around it, and, finally, what hobbyists are building with those.
If you go into real computers, the C.H.I.P.[1] is quite an interesting device. It's $9, which is price competitive with the ATMega644 chip (in single quantities), has WiFi, Bluetooth, and runs Linux. It's also got lots of GPIO, like the Raspberry Pi, so it can be used in places where a microcontroller might normally be used.
I'm sure there are others, but these are the two that are on my radar at the moment.
[0] https://en.wikipedia.org/wiki/ESP8266
[1] https://getchip.com/