Musicals tend to be more my thing. Currently it's still a tie between Wicked and Beauty & the Beast. Although, I love belting out a good Sound of Music song every now and then.
Ace Combat 2 OST, and some with vocals, songs from other editions of the Ace Combat series.
Silent Hill 2 OST, and also with vocals, some songs from the game Silent Hill.
sweatdrop
...Is difficult to name a single song I like, especially in the games...