Use einthusan.tv. Use vpn if you’re in India. It’s free with ad. Subscribe to get ad free. You can download the movie with video downloader extensions in your browser. Using vpn might also block the ads. So you can get an uninterrupted streaming. All the movies in the site are the versions allowed by censor board for Theatrical release. So mostly not butchered with abrupt sun tv censor.
And Tamilyogi. It contains all the dvd versions of the movies.
Edit: If you’re outside India or using vpn, most movies are available on YouTube. Channels like United India Exporters, Ayngaran, AP International have full length theatrical versions of the movies available in their channels.