The first thing to understand about Linux is there is no "best" disto
All Linux distros start with the same Linux Kernel. Then the distro developer fine tunes his distribution to appeal to the audience he wants to reach.
Red Had (Fedora) is your rock solid, enterprise class back office server distro. So do not expect it to play videos and run sound cards out of the box. It can, but you have to work at it.
Suse(OpenSuse) wants the basic office information worker. First class support for Word Processing, Database Manipulation, and general office software. Fun and Games - not so much
Ubuntu, Linux Mint and many others attempt to provide the "desktop experience" How successful they are depends on what you want to see.
Then there are specialty distros too numerous to mention. But if you need them, they are out there.
Ubuntu and Linux Mint are good places to start for an "average Windows user"
Please be aware there is a great gap between the "average Windows user" and the "average Linux user"
As a Windows user when you hit the F1 key in Windows or click on HELP you get menus, lists and pages of help files. How much help is really there is open to debate, but there is more there than most people are willing to read.
No commercial Windows program would ever, ever tell you to open a DOS window.
MS would cut them off at the knees.
Click on help in a Linux program, and if your really lucky, you will have a link to a web page that might have some documentation.
But in many cases, you can be greeted with an "Under Construction" tag and left twisting in the wind.
That's a shock to most new Linux Users. They do not understand that there is far more help and far better help available for Linux, but you have to go to it. The mountain does not come to you. Because they do not understand, they just say, "This is *#rap" and go back to Windows.
But if you persevere, you find a whole different world.
Type an error message into Google and you will find hundreds of hits, that link you to exhaustively detailed instructions as to how to solve the problem.
Go to forums and you can find reams of information. One of the real challenges of Linux is not finding help, but filtering all the information so you can use it.
But then comes the next shock
Many of these answers start with "open a terminal window"
And 60% of the new Linux users have an immediate brain freeze, their hands start to sweat at the thought of "using the command line" and run back to Windows.
But for those that fight through the fear, they find the power of BASH, and learn that every Linux program is a command line driven program first, with a GUI hung on at the end of the job.
They find the real power of the programs are in the command line. You can do most of the basic tasks from the GUI, but when you have to get down and dirty, the command line is king.
So dive in and look around, it's different, it challenging and it's fun.
Welcome to Linux