My absolute favorite game of all time is definitely Chibi-Robo!: Plug Into Adventure for the GameCube. It was the go to game of my childhood. I remember getting a feeling in my stomach knowing it was Friday and I could go home and play it all weekend. My best friend and I first became friends because we both had the game and that's not a very common thing.
I have played through the game countless times. I used to get up early in the morning and see if I could get through it in one sitting. It was the game I played when I was at home sick, the game I went to when I was just bored, or when I wanted adventure or a weird game with a good story. I spent many hours cleaning the Sanderson's house, exploring, driving a hot rod, flying a space ship, climbing a castle, time traveling, or going through boot camp to battle a dog. I never got tired of it no matter how many times I finished it 100%.
Even now that I'm a lot older, I still adore everything about it and the adventures I had in it. It's been over a decade since it came out and nothing has really gotten close to topping it for me. I recommend it to any Nintendo fan.