Another vote for Linux Mint.
I spent some of the weekend playing around with a very old laptop (Compaq N610c, 1.8GHz CPU, 1 GB RAM, 40GB HDD) and decided to try installing Linux Mint 16 with the MATE desktop.
It was altogether a very positive experience - no installation problems at all, it even found and configured an equally old D-Link cardbus wifi adapter (wireless card support had been a major stumbling block in the past). The only issue I had was that the laptop doesn't support boot from USB, so I had to burn the ISO to a DVD and the installation was a lot slower off DVD.
For a Windows user I found the MATE desktop very easy to navigate.
OK, it's not blisteringly quick, but for a 12 year old laptop it's not at all bad. The last time I had used it was 2008, and XP & office XP performance seemed acceptable - it's a bit slower, but not much, with libre office.
I intend to use it as a learning tool, to get under the bonnet of Linux, so performance isn't that important.
I downloaded and installed a few packages - very slick.
A complete OS and application suite for zero cost, very easy to install, configure and use - what's not to like?
Impressed.
SD