It started when my daughter got Leukemia (we're almost 2 years on now, and she's doing well). A cancer charity bestowed her with a Netbook computer running Windows 7 Starter. While delighted to have her own laptop computer, she often complained of "how slow" it was. Looking it over, it was clear that even the Starter edition of Windows 7 could be a drag on this resource-limited machine.
I already use Ubuntu via VirtualBox for software development and testing at my work. Therefore, my first attempt at resolving this for her was installing Ubuntu 12.04 via the Wubi installer. She liked it, but a month later was still complaining of performance issues. Sure enough, Unity was just too heavyweight for the little system to "just work nicely".
After searching around. I found Peppermint OS, an offshoot of Lubuntu that is focused on giving a Chromebook-like experience via Chromium and "desktop web apps", but without sacrificing the ability to be a general-purpose Linux computer. I installed it as a proper dual-boot option on her netbook. She loves it, and it even got a positive response from all other family members who have borrowed her machine from time to time. A few weeks ago, I provisioned a 2008-era Core 2 Duo Dell laptop for my wife with Peppermint OS as well. Total cost: $47 ($5 to take it off my workplace IT department's hands minus power supply and hard drive, $4 for a power supply, $38 for a 120 GB hard drive)
See the next post for how I'm gradually migrating our living room PC from Windows 7 to Linux as well. This one is more challenging because it's my little ones' "game machine" as well as our Netflix/Amazon Video/DVD/Blu-Ray box.