Just about any main popular distribution should qualify, testing a few is probably the only way to find one that's compatible with the hardware and that the intended user likes.
The distribution question is important for stability (like Debian's stable/testing/unstable), hardware & support & release model (fixed, rolling), but probably secondary to the question of which desktop environment (DE) they prefer. There are more than a few DE's pick from. See this Q for a brief overview: What kinds of desktop environments and shells are available?
A Virtual Machine (like VirtualBox or VMWare) is an excellent way to try out the "feel" of different Linux distributions. But, it won't tell you how they'll actually run directly on your hardware (a Multi Boot USB that can boot multiple ISO's would be great for that).
I really like Linux Mint. Comes with most of the things pre-installed that you want to use, not just web browser, email & word processing (almost every distro has those), but the non-free stuff that you'll usually want to install to other distros after installing. Like video/audio codecs (plays most every video/audio format you'd want & video DVDs), a flash player already installed (or waiting for a one-line install).
It's based on Ubuntu and shares their software repositories, almost anything that Ubuntu can do (like PPAs) Mint can do too. Ubuntu's based on Debian, so uses
dpkg package management, and Mint can do almost anything Debian can too. It's like getting 2 major distributions PLUS good stuff... (Ubuntu++?). When Ubuntu embraced the Windows8-like Unity desktop, Linux Mint stayed with more traditional desktops that many users (like me) prefer.
Linux Mint has several different "editions" based on different desktops (Cinnamon, MATE, XFCE, KDE), they're listed with screenshots on the Linux Mint homepage, and there's also a rolling Debian edition based directly on Debian (currently LMDE2 based on Debian Jessie).
Mint's "main" Cinnamon edition looks quite nice, and usually is ready a few weeks before the XFCE & KDE editions
Mint's XFCE edition has been very stable for me (it's my favourite), and has the "classic" desktop look. Very similar to old Gnome 2 & MATE.
KDE is supposed to be more windows-like and an easier transition for windows users, some of it's programs are especially good, like k3b (cd/dvd writer) & kdiff3 (visual diff).
Linux Mint is also currently #1 (since 2012 to now-2016) on http://www.distrowatch.com which is an excellent site for searching through the different Linux (& BSD & other) distributions.
SELECT count(*) FROM available_distributions WHERE 1=1– that matches almost all of them (OK, give you a point for "ease of use"). Will be pretty much opinion-based. I'd say take a look at Linux Mint – good for starters, easy to install. And even my wife was able to use it right away :)