A few artists to check out if you haven't already done so:
Nick Drake (espescially "River Man")
The Cure (espescially "Lullaby")
Black Rebel Motorcycle Club ("Generation")
David Gilmore (Any solo stuff but in particular the album "On an island")
Lyndsay Buckingham ("Bleed to love her")
Richard Ashcroft (Listen to the album "Alone with everybody" through headphones, there is so much going on in each track that you can listen to it over and over and hear something new every time)
Thea Gilmour (Really good british female songwriter. Sounds better live though.)
Blueman Group (Just for something different. Try searching for them on youtube!)
Thomas Newman (Composer behind a lot of the best movie soundtracks. Something haunting about all his music)
Alan Hull ("Hate to see you cry" beautiful song)
Brett Dennen
Damien Rice ("Blowers Daughter" On e of my favourite busking songs)
The Frames (Great irish band - check out the lead singer - Glen Hansard - solo stuff too. And the movie he stars in called "Once")
TOO MANY MORE TO LIST!