I have a few rhythm game I love.
First of all, I love Cytus. And Cytus 2. (Yeah, its a second Cytus, but with a completely different story.
And they also have Deemo and Voez (I like deemo, but not so much with voez).
I just downloaded a game called Muse Dash. a mix of rhythm game with the rpg running dash (I don't know what it's called).
There's a few others that I've down loaded before with an awesome story, music and gameplay, but I forgotten the name. But anyway, just try playing Cytus 2. The story is really good.