I'd second the opinion of Ubuntu/Kubuntu. I've tried nearly every version of Linux there is, alot of them via Live CD, several I installed, only to have so many problems with them, I abandoned them.
The two easiest/best versions I've used, is Ubuntu 6.06 and Fedora Core 5. I've heard many good things about Gentoo, but I seem to recall installing software with Gentoo a bit more difficult(had to be done from source). Ubuntu uses Apt-get, which makes downloading and installing software extremely easy. FC5 uses Yum, which also makes installing software very easy.
Of the two, I'd probably recommend Ubuntu(or Kubuntu, depending on the interface you prefer)