I'll second the Opeth recommendation... some really awesome stuff! The songs I've heard from the new upcoming album are also very good, I can't wait to hear the whole thing.
Some of my recommendations:
Hybrid - Breakbeat style electronica with a real cinematic feel... check out Wide Angle, Morning Sci-Fi, I Choose Noise. They also have some new stuff coming up which should be awesome.
The Cinematic Orchestra - Awesome modern jazz/electronica. Motion and Every Day both rock.
Porcupine Tree - Prog rock/metal. Fear of a Blank Planet is pure awesome.
Imogen Heap - Pop. Speak For Yourself is an outstanding album.
Wax Tailor - hiphop/turntablism. Tales of the Forgotten Melodies, and Hope and Sorrow are some of the best I've heard in a LONG time.
Bonobo - Downtempo electronica. Animal Magic, Dial M for Monkey, and Days to Come are all very good.