EarthBound. Which might seem a little strange, since it actually seems like the sort of game that would turn people AWAY from RPG's.

But something about its down-to-earth humor and its funky battle system/music really drew me in. I was addicted from the first time I played it at my friend's house.
And then came FF V...I had a LOT of fond memories of that game from when I was younger, so it had a bit of an extra nostalgic/sentimental value for me.
And of course, FF VII...the newb's FF. Materia confused me for the longest time, until I realized that it actually WAS as simple as it looked.

I still think it's one of the best magic systems ever created.
Super Mario RPG is also a good one to start with before getting into the more "hardcore" stuff. Cute, easy, and above all, FUN.