Animal Crossing: New Leaf is easily the best Animal Crossing game, bar-none.
For this installment, you start off riding on the train with Rover, like you did in the original Animal Crossing for GameCube. After you arrive, you find out you are mayor of this town, so you call the shots! One great thing about this game is that if you have mayoral privileges, you can basically do anything you want to your town! Other players using the same Game Card have to follow your orders as citizens.
Features available for all are...oh man, I can't name them all, so I'll name a few. Multiplayer, Re-Tail, changing town settings (town tune, flag, etc.) Club 101, Shampoodle, Dream Suite, viewing model homes, museum donating, so much to discuss!
Re-Tail lets you sell your unwanted items and just random items for bells, which are your currency in this game. Club 101 lets you listen to K.K Slider's rockin' tunes! Shampoodle lets you play as your Mii, or at least lets you get a new hairstyle. The Dream Suite is awesome. It lets you view random towns from all over the world. You can also enter specific codes that take you directly to the town you want to view! You can take home designs from towns you visit and add them to your town! So even if you don't have the mayor of that town on your 3DS friends list, you can still visit their town. The multiplayer lets you do everything you can in Animal Crossing: New Leaf regularly, but with up to 3 other people. Actually, let's discuss how you do this. You have to either open your town up, or wait for a friend to open up their town. Since there's essentially no way to communicate with your friends over a chat application on the 3DS itself, meeting up with friends is a convoluted process. At least it pays off when they arrive.
Graphically speaking, this game pretty much shits on almost everything in the 3DS library. (Other than Kid Icarus: Uprising) We went from the graphics of the previous titles which weren't anything special to something breath-taking. The atmospheres change throughout the seasons, and they are fantastic looking especially at night. The music in this game captures the said atmospheres and the music can range from a happy tune that I can take a nice, brisk morning walk through my town to, or a deep tune that has you lost in though. Can't get enough of the music.
Overall, ACNL deserves a GOTY nomination. GTA V will probably win the whole thing, but here's to an awesome contender!