I love radio, so I have all the radio channels, Shoutcast, TuneIn, AccuRadio, Live 365, etc. Most of the "free" movie channels I didn't bother with; it wasn't so much the commercials as that the commercials made the Roku crash a lot. In fact, I now won't add any tv channels that have commercials or that cost money.
One exception: I paid the $2 or whatever it was for Pub-D-Hub Gold, which fills all of my very-old-movie-and-TV needs nicely. Also have Smithsonian, although I find their narrative style to be a bit over the top. I have Amazon, but I cancelled Netflix a while back. MLB.tv is great, because they show a FREE GAME every day, with no commercials, it's amazing. PLEX is nice for playing youtube videos on my tv. I just added NFB Films, which looks excellent, mostly Canadian documentaries.
I wish very hard that the Metropolitan Opera would fire up a Roku channel for their opera rental service. I would rent many many more operas if I could stream them to the tv. I emailed them about it, but they suggested I hook my computer up to the tv instead; I wonder, given the demographic makeup of their audience, if this is the best suggestion.
I just use Netflix, Amazon and Hulu Plus, haven't really found anything else worth adding. I'm pissed that Comcast won't let me use HBO to Go on my Roku even though I pay for HBO and 4/5 of the stuff on HtG isn't on Comcast's On Demand thingy.