Netflix is definitely the best subscription service. They do have
some brand new releases, but not the most popular ones. If you're talking specifics, Redbox doesn't even have the
newest releases either sometimes...their release schedule is behind on certain movies so you still have to wait 1,2,3 weeks to rent from Redbox.
Anyway, the most recent example of Netflix is that I rented Happy Christmas from Redbox several weeks ago and I see it's now on Netflix. Terrible movie, by the way.

Netflix streaming does have a lot of newer releases, but not always the one you want. I use both Netflix and Redbox (and occasionally an actual movie rental store if I'm really excited to see a movie right away).
I love the Netflix Original Series selection.
Amazon Instant has the worst interface ever (along with Hulu Plus) and it just doesn't have much for me. Some people love it.