Technically, your question is "which distribution"
not "which operating system" Linux is the kernel
of the OS, and there's only one Linux kernel.
Hardware issues aren't as important now as they were,
but obviously you want a distro that works on what you
Aside from that, I'd advise picking one that ppl you
know in "real life" use... look for a local Linux User
group. Last week at NYLXS (http://www.nylxs.com
was present at a SuSe install that was almost effortless.
Lots of *lugen have installfests. It's a good way to
get through your first.