Pat Metheny and Charlie Haden - Beyond The Missouri Sky (Short Stories)
Look no further. Everyone needs to have this record whether you think you like jazz or not. I have and like most of the records listed above - but none convey "nighttime" or "peacefulness" as this one does IMO. The songs are mostly old and classics - though not as recognizable as Misty but they will grow on you.
From Amazon review: This subtle, sublime collaboration finds bassist Charlie Haden and guitarist Pat Metheny crafting bejewelled chamber duets that transcend genre. Haden and Metheny forge a lyrical, mostly acoustic style at once intimate and expansive. Both pare their playing to a Zen-like economy, focusing on a purity of tone, clarity of harmony, and counterpoint to achieve a tender lyricism.
From a user review on Barnes&Noble.com: This album is easily the most-appreciated album (cd) that i have ever played for friends and family. To the person, every one that i've played this for has appreciated it, and wanted a copy of their own. While it strikes at first as background-like in tone, a closer listen reveals gorgeous warmths of peace and reflection. You can't help but feel appreciative and evocative as the beautiful melodies and colors cause your feelings to echo the sound. You'll feel peaceful, calm, and positive.
We are listening to it right now because in fact my son has used tracks from this as his nighttime lullaby album almost every night of his life. It is not "jazzy" per se or "night clubby" - it is much more pure and harmonious and restful. Took me a few listenings to appreciate it.