With the rise of internet video distribution, there’s a lot of buzz over who provides the best service. Rather than go into it myself, I’ll refer you to someone who already has.
I’ve used Netflix and iTunes for movies, and I’ve recently subscribed to Vudu. Vudu offers the best HD movies, but it is pricier. However, Netflix’s online library cannot compare to iTunes or Vudu. iTunes is great price-wise and library-wise, but it does not have the highest quality movies.
Anyway, I wish you happy viewing!