Jazz for relaxation

I would suggest 'Beyond The Missouri Sky' by Pat Matheny and Charlie Haden, both Missouri boys. Two acoustic instruments and very melodic. You should be able to find it at Tower, Barnes & Noble, or Borders.

Tord Gustavsen "Changing Places"
Tomasz Stanko "Soul of Things"

Bob's lastest List:

KENNY BARRON IMAGES VERVE
VINCENT HERRING MR. WIZARD HIGHNOTE
GREG OSBY PUBLIC BLUENOTE
CHARLES BLENZIG IT’S ABOUT TIME DOUBLE-TIME
JOHN SCOFIELD ENROUTE VERVE
WAYNE ESCOFFERY INTUITION NAGELHY
RICK SIMERLY OBSCURITY DOUBLE-TIME
JOHN LA BARBERA ON THE WILD SIDE JAZZCOMP
RUSSELL MALONE PLAYGROUND MAXJAZZ
JOAN STILES LOVE CALL ZOHO
STEFON HARRIS EVOLUTION BLUENOTE
JERRY BERGONZI LIVE GONZI DOUBLE-TIME
WARREN VACHE DREAM DANCING ARBORS
PETE MALINVERNI THE TEMPEST RESERVOIR
TOMASZ STANKO SUSPENDED NIGHT ECM
TINEKE POSTMA FIRST AVENUE MUNICH
MEL RHYNE TOMORROW YESTERDAY TODAY CRISSCROSS
MULGREW MILLER LIVE AT YOSHI’S 1 MAXJAZZ
STEVE DAVIS MEANT TO BE CRISSCROSS
DAVID KIKOSKI DETAILS CRISSCROSS
GIACOMO GATES CENTERPIECE ORIGIN
BILL CHARLAP SOMEWHERE BLUENOTE
DAVID LEIBMAN IN A MELLOW TONE ZOHO
MARK EISENMAN SWEET & LOVELY CORNERSTONE not available
MIKE LEDONNE SMOKIN’ OUT LOUD SAVANT

Since you mentioned you don't want any vocals, my recommendations are as follows :-

1) Fourplay - almost all of them are good
2) Acoustic Alchemy - The Best Of, Radio Contact
3) Earl Klugh - Collection album(somebody mentioned earlier)
4) David Benoit - The Best Of 1987-1995 (piano)