As in almost everything, the "best" is subjective.
I will give a little story.
When I first start to work with LaTeX (5 years ago more or less) and when I used Windows, I used
WinEdt as my editor for LaTeX. It was good, because it had some options to insert LaTeX code that I didn't know. If I wanted to insert some symbol, I would simply use the mouse and try to find the symbol and them add it by a click on the mouse.
When I changed to Mac platform, I used something similar to Winedt, it is
TeXshop. When I migrated to Linux, I started with
Kile, which is a good and free editor, but I wanted something more powerful, fast and robust, them I found
VIM which is everything that I needed, BUT learning VIM is not so easy. At first can be quite discouraging, but after you start learning it, it is quite natural. Finally, I use
Vim-LaTeX which is LaTeX with a bunch of macros, that will ease even more the typing of LaTeX and give proper LaTeX highlight.
Since you are starting to learn LaTeX, I think the best choice is something like Winedt, and after you know many of the LaTeX codes for the symbols, than you can try other editor. But remember that learning LaTeX can be quite discouraging at first.