I've just got my Raspberry Pi and then I faced the question: Which Linux OS should I use with the Raspberry Pi? I'm aiming to use the Raspberry Pi for forwarding commands from connected Android devices wirelessly to an Arduino board.
What is the best OS for that and what programs should I get in order to achieve it?
It depends on what you want! NOOBS is the all around favorite and most suggested for beginners, as it is simple and makes the setup of the Raspberry Pi very easy. NOOBS is the top option on the RaspberryPi.org downloads page and is the officially suggested option by the Raspberry Pi Foundation. However, NOOBS is simply the way to install the OS', it isn't an OS in and of itself.
To help choose the OS:
If you are going for a full fledged, easy-to-set-up distribution, I would use Raspbian, as crazyskeggy suggested. It is the suggested OS for beginners, as it comes pre-installed with many packages that are useful, and it is easy to set up and control. Raspbian is based off Debian, a popular Linux distribution. Raspberry Pi Fedora Remix, AKA Pidora, is also another beginner-ish OS, though it is different than Raspbian.
However, if you want a fast, in control of everything and anything from the beginning, I would use Arch. Word of Warning, Arch isn't for the average beginner user, as you have to download and install everything, as Arch starts after installation and plops you down in front of a command line with limited packages. You have to install all of the X packages and most non-essential programs. While this gives you control over your system at a very low level, it makes it a very non-beginner-friendly option.
If you want something different, RISC OS is something to look at. It behaves quite a bit different than either Raspbian and Pidora and was originally created for the Archimedes computers created by Acorn that ran on ARM CPUs. It is actually quite old, being introduced in 1987, though many people still like to use it on the Raspberry Pi.
Finally, if you are going for a Home Theater PC, there are three options: XBMC, Raspbmc, and OpenELEC. Only Raspbmc and OpenELEC are featured on the Raspberry Pi downloads page, though you can find the download for XBMC simply by googling around.
Raspbian is the recommended distribution to use, and contains a large number of applications in its APT repository.
There is also a large number of Raspberry Pi tutorials on the internet, which usually use apt-get, the Debian package manager found on Raspbian, so it's always good to start there, unless you know what you're doing with other distributions such as Pidora, a Raspberry Pi Fedora remix.
