I liked the Sally Sparrow episode. The Doctor said his best line ever about time being all "Timey Wimey,Wibbily Wobbily"
Beside that I don't know what else this fella has done.
He did The empty Child/The Doctor Dances in series 1.
The Girl in the Fireplace in series 2 (my favorite episode of the new series).
Blink in 3.
The upcoming Silence in the Library/Forest of the Dead.
He also wrote recent BBC miniseries Jekyll, and classic comedy Coupling.