Ben Folds has compiled a collection from his archive called The Best Imitation Of Myself: A Retrospective (1995-2011):
CD 1: The Best Imitation of Myself
CD 2: Live (1997 – 2011)
CD 3: Rarities (1991 – 2011)
There will be a one disc edition (CD1) and a three disc set. If you preorder it on his website you'll get also a five song download code from the new “Ben Folds 55” online vault (a collection of songs only available online - more details coming soon).
By the way, the set includes three brand new tracks with Ben Folds Five!