I'm definitely a Pathfinder evangelist, but it isn't my favorite genre or the one I'd most highly recommend for a newbie (unless you are just really into the setting). I recommend trying Chronicles of Darkness out if you want a game that is actually both isimple at it's core and easy to add content to, it's what i recommend newbies every time.

The base systems are easy to grasp and mostly applies to every part of the game, the point buy system makes it simpler to follow character advancement (no set growth so you only need to remember what's on your character sheet), and the setting is incredibly easy to grasp (well, the parts you are supposed to know, it's just slightly worse earth with vampires and werewolves and mages oh my).