Air
This is a French duo who create lush sound scapes mostly via Moog synthesizers, Wurlitzer organs and vocoders - which makes it surprisingly easy to replicate their sound live.
They have quite a few albums but everyone would agree you should start with the now classic,
Moon Safari:
Quite a few of these songs have been used in film, TV and ads...so I'm sure you've heard at least a couple of these:
All I Need (warning - bad fan video!)
La Femme d'Argent
Sexy Boy
Kelly Watch The Stars
Their most popular song is probably the Theme from the movie
The Virgin Suicides:
Playground Love
Great band, fantastic live, too...