For a seasoned programmer Arduino or something else?
I am also a software guy by day. About ten years ago I got started with BASIC stamps from Parallax, and after a long lapse I recently got back into embedded projects. Initially I looked at the Arduino and its different parts and realized that I could just skip past the price tag of the Arduino board and grab some ATMega168s and get started again. This worked for the most part, however I frequently ran into issues where having a prebuilt board would have been nice since I couldn't have screwed up the basic assembly.

I eventually ordered an Arduino and love everything about the board and libraries. I'm not a fan of the "IDE" so I click on 'Use External Editor' and use the IDE purely for compiling and flashing the software to the board. Usually I start a project or idea with the Arduino board and then port that into a mega chip. This helps at keeping costs down by using only necessary parts for a project but it still allows me to quickly come up with a prototype. 

Good luck!