See the Cinema & Media Studies Research Guide, which has a page "What films can I stream right now?"

To do a keyword search for films that interest you, search the library catalog and limit to Format: Video.

For ideas of what to watch next, or to create a personal watchlist, see useful apps like JustWatch, Letterboxd, or IMDb (the Internet Movie Database). You can also read reviews and articles in film journals and magazines.

Additionally, the Cinema & Media Studies Research Guide has a page featuring lists of the best films of all time.