I watch YouTube on my Roku. It’s been on mine a few years, not sure if I got the link from the forum on Roku’s site or if its in their offers. It pulls in my favorites and ones I’m subscribed to. I use it mostly to watch Red Eye, full episodes are uploaded the same week they air.
If you get Youtube you should try the “James Burke” channel, the shows are old but usually very interesting
There are also Youtube channels with westerns, John Wayne, war movies and horror movies.
I tried to find it by checking their channel listings, no luck. I watch a lot of YouTube content, mostly on my Apple TV in the family room. But would like to get it on my Roku in another room. Another thing I noticed, is that the menu capabilities on the Apple TV puck are easier to use with more features, especially with Netflix. Roku has Angry Birds going for it, but without YouTube the Roku doesn't get as much use.