Laid back, mellow, sax/jazz

"The Gentle Side of John Coltrane", or his "Ballads"

gene ammons' classic '' boss tenor ''.
arne domnerus quartet '' easy going ''..fantastic recording.

How about Kenny Burrell's "Midnight Blue", a very after hours jazz/blues vibe.

There are some good suggestions above. I agree with the Paul Desmond post. He was consistently the most beautifully lyrical, sweet player that I have ever heard (alto) and I am a serious collector and listener(35 years).There are many titles in his catalog to try, Pure Desmond, From The Hot Afternoon, Two of A Mind(with Jerry Mulligan)and others.Scott Hamilton is another guy who always seems to please. Titles to listen to are, Plays Ballads,Soft Lights Sweet Music(a Gerry Mulligan Scott Hamilton disc) and After Hours. Coleman Hawkins and Ben Webster should always be given a serious listen, again many titles here There are some great artists and titles in this genre, I could go on and on.Enjoy the music,that's what it is all about.

Anything by Ben Webster, particularly with Art Tatum and Oscar Peterson.