Anything from Perry Como on 78rpm .... it makes my mixes sound really good.
Actually no, I don't use any reference commercial stuff. I do appreciate the clarity, dynamics, and overall sounds of lots of cd projects..... Alison Krauss is a favorite..... I listen and hear things and then go to the studio and try to replicate as best I can that certain sonic characteristic. But I don't play that music through the studio and compare.
Perhaps it's the tone of a mandolin, or the reverb on the vocals, or something else entirely....It catches my attention and I listen to try to figure out what they're doing to get that sound, and then, how could I do that in my studio with my gear and skills?
I simply strive to be able to hear every instrument in my mix clearly and have it sound as natural as possible, and fit properly into the mix. Same thing with vocals. So, I guess in a way, as I'm listening to any commercially produced music, I'm listening critically and dissecting the the mix to see what truth I can glean from it that is applicable back in my humble studio.
Almost in a monkey see monkey do sort of way. Does that count?