I want an easy to use Linux
Ubuntu is the default answer for anyone looking just for an easy-to-use desktop Linux with a huge, friendly user community who are ready to help. It has that reputation for a reason: Ubuntu really is easy.
What Ubuntu doesn't come with, by design, is some popular proprietary programs such as Adobe Flash or Reader. If you want those programs, but you don't want to bother tracking them down and installing them with the Ubuntu Software Center, what you want is a Linux distribution that comes with these programs either already installed or makes it really easy to install them.
If that's you, what you want is Mint or Novell's openSUSE. Mint is based on Ubuntu but includes most of the more popular proprietary goodies. I've used Mint a lot and I've grown quite fond of it. Indeed, for users who just want something that's simple to use and comes ready to work with Flash, PDFs, and the like, it's probably your best choice.
OpenSUSE is also an old favorite of mine, but it's more of a business desktop distribution, which reminds me...
I want a Linux desktop for my business.
Red Hat has a business desktop, but Novell puts more effort behind making their Linux desktops work and play well in corporate offices. If you want an official, fully-supported business Linux desktop then Novell's SLED (SUSE Linux Enterprise Desktop) is the one for you.
I've been using SLED for years and, as far as I'm concerned, it, not Windows, is my business desktop of choice. It's easy to manage, simple to upgrade, and far more secure than Windows will ever be. Besides, it also fits in nicely with Windows Server-based networks so you can slowly migrate your way from Windows to SLED while keeping your existing AD (Active Directory) network infrastructure.
Another plus in SLED's favor is that you can always try its community-based little brother, openSUSE first. I use openSUSE myself both on desktops and servers and I've always liked it. If it works for you too, you can then move up to full corporate support with SLED.
Next page: I hate, hate, proprietary software.