I've only heard a few complete sets of Debussy, and my favorites out of the ones I've heard are Paul Crossley and Jean-Efflam Bavouzet. Both are very technically articulate and are relatively innocent from a musical standpoint, which I believe is what you want in a complete set. Both are great from an "encyclopedic" standpoint, in that they give you a great picture of the work without showcasing the performer's ego a gross amount.