HBO Max is free with DirecTV. If you subscribe to HBO that is. You also get Showtime Anytime, and all the other paid for premium channels streaming channels if you have them in your DirecTV package.
Also..... Many channels have a streaming version of that channel on your Roku, AppleTV or FireTV. FX, Starz, AMC, ESPN, HGTV, CW, etc. Some parts of those channels will have commercials though so be aware. And some will have limited or zero commercials if it is part of your subscription on DirecTV.
P.S. HBO Max is a Cine-file's wet dream. I have never seen such an amazing movie portfolio since I got rid of my Criterion channel subscription. Truly an immense portfolio of new, recent, & classic movies from all generations & genres.
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Most channels have an On Demand version of that channel in the 1000's IF your DVR is connected to the internet. I have always found it to be slow even though my internet connection is basically lightning, so I blame that on the DVR interface personally.
With that being said there are some free movies up in some of those areas, but I have never really dove in.
For example, Channel 501 is HBO. Channel 545 is Showtime. Channel 1501 and 1545 are the On Demand channels for both.
FX, Starz, HBO, Showtime, AMC, HGTV, and many more all have On Demand Channels in the 1000's.