[nileshtrivedi]

Texas Instruments practically gives away their development boards. Here is their Stellaris Launchpad board with ARM Cortex-M4F-based MCU for just 8$! Much cheaper than even AVR arduinos! https://estore.ti.com/Stellaris-LaunchPad.aspx

What's more, these days you can even use the Arduino IDE for development on these boards. The Energia project has ported Wiring and Arduino IDE for TI boards. If I wasn't such a minimalist, I would get one (or two) in a heartbeat!

Edited: Forgot to paste the link.

[mindslight]

The TI offerings look geared towards low power and are kind of anemic on the high end with up to only 32kB ram and 256kB flash. ST/NXP/Atmel have parts with over four times that (and the ST eval board is also only $15). I know you can do a lot with a little (I used to design with pic16), but for higher level languages without runtimes optimized for embedded (eg rust), I'd want all the room I could get.