I use ubuntu , It has some quirks to get the Arduino IDE running and the serial port monitor working on 64 bit but it is a good and very popular flavor of Linux. Centos is another ( The free version of RedHat ). Bear in mind that at the core they are all pretty much the same based on the kernel you are using. The look , feel, software packaging, desktop , are all varied by the different distributions ( distro's ). I have gotten it all working properly for Ubuntu 8.10/9.04/9.10 so I can share the tricks needed. If you are using an older PC with 32 bit then I think there are no problems.