Those of you who use them, already know that, though

I haven't used reference tracks as much, yet, but now I have narrowed at least some albums some down to use in my mix templates. I keep returning to three albums I really like, Colbie Calliat's "Falling for you", John Mayer's "Continuum" and Mat Kearney's "City of black and white". Some of these tracks are a bit overlapping into pop/rock land, though..
Care to share which favourites you pull up for singer/songwriter productions?