Well... I finally finished EarthBound. Touching game.
In the long run, I'm not going to remember it for the gameplay, but rather for the personality of the world. The way Itoi created the characters made me want to talk to everyone, a normally tedious task. Combine that with the amazing music, and you've got a game with a great atmosphere too. I also like how the game felt very personal to the player... all the way to the end.
Another big thing for me was how I related a lot to Ness. This may just be because of how ambiguous his personality was, but even still... His family, experiences (to an extent), and feelings all reminded me of my own life. Heck, he even has a blond friend who works in a preschool with whom he only has a slightly awkward relationship with.
With that said, I was surprised I didn't cry at the end... and then I realized, the game reminded me so much of myself, I'd already shed my tears in real life.
TL;DR version: EarthBound is phenomenal, and I can apparently can write an emotional paragraph.