Before watching a movie, I usually like knowing what I'm getting in to. Is there any way to watch the movie's preview from Netflix? I mainly want this for movies I can watch instantly.
Some movies have a "Play Trailer" button on the top right corner, under the "Play", "Add to Instant Queue", and "Add to DVD Queue" buttons. It's pretty hit or miss (mostly miss), so if there's no trailer button, you will have to search on YouTube, Google, or some other video search engine.
Google Search: "[Movie] Preview" or "[Movie] Trailer"
It's probably on YouTube.
You can use the Netflix Trailer Button Adder Chrome extension to add a "Watch Trailer" button below each film on the Netflix discovery page.
I typically use i.TV (or GetGlue) in order to see clips from TV shows, trailers, and videos of bands/musicians.
i.TV has an alerts feature to remind you that a new episode of a show you have 'favored' is available. It also provides links to the services that the show is currently available from. Services include: Netflix, iTunes, Hulu, live network television/cable, etc.