The music I love to sing would have to be gospel - it just uplifts me, it takes me to a really good place.
I prefer to sing in the shower vs. the car. The shower is just steam, you know, its just you, and nature, and no clothing. You know, there's nothing separating you. It's just you, and the voice - you, and the water.
The type of music I like to sing is really those classic songs, those Barbara Streisand, Celine Dion, Frank Sinatra, classics.