Ok I am a music lover extraordinaire and I will not lead you astray.

Relaxed smoking music similar to Zero 7:

Thievery corporation (Album: mirror conspiracy)
Broken Social Scene (Album: feel good lost, has nice piano @ instrumental synth)
Chroma Key ( ALL albums: Dead Air For Radios, Graveyard, Mountain, Home, You Go Now (start with this one)). Very good vocal work here with a lot of sounds and ideas you have probably never heard before.

Just plain good music:

Bright Eyes: (Album: I'm Wide Awake It's Morning) great chill music with calm acoustic guitars and soothing male vocals.
The Crystal Method Album: Tweekend (awesome electronic / dance with some pretty intense beats and harmonies at times. Definitely check this one out.

Shpongle Album: Are you Shpongled? (This stuff is GREAT! very little talking or singing, but when there is it is tastefully done. Shpongle is for when you are feeling in a very weird relaxed mood. It combines various elements of synth and new age only without the annoying beats and repetitive hooks.

Enjoy!