Cory in the House is a classic through and through.
After my 5th play-through of the game I still found myself discovering Easter eggs and unlocking sidequests I didn't even know existed! Also, the variety of interactions and dialog paths you can engage in with the assortment of NPCs makes them feel so real. It really gives the game life, along with the incredible graphics.
The accompanying soundtrack adapts to the area of the game you're in, and varies based on your playstyle. It truly feels catered to the point where it's like I am actively participating in a Cory in the House movie.
I have played dozens of DS games, and although I am a huge fan of the Legend of Zelda series, this game tops the charts in terms of story, music, graphics, replayability, and more. I cannot recommend a game more than I recommend this masterpiece.
Even if you have not watched the original anime on Disney, this game will surely inspire you to.