Lots of stuff to do and places to go. Neighbors have big overarching aspirations. Many unique personalities rather than 6 personality archetypes. (I don't know if AC NL fixes this.) The non-neighbor characters seem like they have personal lives rather than wait for you to show up so they can repeat their canned dialogue. And rarely, something really incredible happens.
Any fan of Animal Crossing should watch it, of course. Here are some screenshots of what I'm talking about -- but you really should watch it if you like the games.