Netflix’s "Downloads" feature saves movies to your device in a high-efficiency MP4 variant. However, you must use the official Netflix app—you cannot transfer the file to another computer. Plans start at $6.99/month.
Apple sells Hollywood movies in high-bitrate MP4 (M4V) format without DRM on some older purchases, but most new purchases include FairPlay DRM. You can download and watch offline on any Apple device or PC with iTunes. Prices range from $9.99 to $19.99 per movie.
Downloading copyrighted Hollywood movies from unauthorized sources is illegal in almost every country, including the United States, the United Kingdom, Canada, India, and the EU. Penalties can range from hefty fines (thousands of dollars per downloaded movie) to, in extreme cases, jail time.