You can't ask what the best Linux distro is...there are hundreds..and everyone has a preferance.
If you're just starting, then opt for Mandrake, SuSe, Fedora, Ubuntu. Any of those are n00b-friendly.
I currently use Mandrake..which grows with you. So as you get better in linux, mandrake will still keep up with you. But that is my personal preference...
Don't get any of those crappy "windows-like" distros...lindows and the like...they suck and are like a bicycle with training wheels that can't come off...ever.
And if you are serious about learning linux, learn the commands...not just the GUI.
And if you just want to give linux a try, there is a very good version called "Knoppix". This will allow you to pop in the cd and run linux without installing anything. That's how I started out..it's great.
http://knoppix.org/