In a blind taste test, 4 out of 5 users couldn't tell the difference between Kubuntu and Windows Vista. Okay, so this wasn't a very scientific survey, but it goes to show one important point: people will use what they have in front of them and as long as it looks new and shiny they'll take your word for whatever claims are made about the product.
Well, I'd like to try something similar, but with you, the survey participant, being told up front: this ain't your daddy's OS. We're talking Linux here, Ubuntu to be exact, and I'm throwing down the gauntlet. I dare any Windows user out there to try Ubuntu for a solid 30 days and report back.
There are enough resources and support forums available that you should be able to meet just about every need with either the same ease as your current operating system or better. And for the skittish, I can even suggest a way to get through the month without partitioning your hard drive: use to download everything you need to boot right from a USB drive. No commitment necessary, and if you decide to keep your new environment, the installer is right there waiting for you.
So go ahead, try something different. The only thing you have to lose is Windows...