Ludovico Einaudi is, in my opinion, the best composer working today in the nebulous field of "neo-classical" or "new age" or "contemporary piano," whatever you want to call it. His music has a minimalist flair, reminiscent of Philip Glass (but more melodic than Glass) or Yann Tiersen. Out of deference to the cranky reviewer below, I won't compare Einaudi to John Reich, except to say that Einaudi's pieces have much greater melodic appeal to me than Reich's. ;-)
Le Onde is a very good album, but not Einaudi's best. The strongest tracks are "Le Onde," "Questa Notte" and "Ombre." If you are new to Einaudi, I'd recommend that you start with the "Echoes" greatest hits collection instead, or "Divenire," his most recent release. If you are an established Einaudi fan, then you will probably want "Le Onde" simply to have a complete collection.
One last comment: Einaudi has released most of the sheet music for his work, and it ranges in difficulty from fairly easy to quite advanced. I recommend highly "The best of Ludovico Einaudi: Piano solo" sheet music collection.