If you're starting off, I'd suggest going with 5e. They simplify a lot of mechanics, and incorporate some of the funner aspects of the old expanded systems right into the core classes. It doesn't have all the crazy awesome bull**** you can pull off in 3.5 or Pathfinder, but it does tend to move a lot more smoothly. It's a sleeker, faster tabletop.
Like a cheetah.
Having played a few games of it on both sides of the table, it's a blast, and new players have a much easier time getting a handle on things.