Personally I use Roku because it's the snappiest experience with the fewest crashes. I started with a Chromecast but its integration with Android was a little too deep: leaving wifi while casting YouTube would cause the YouTube app to hard lock into a "connecting to chromecast" error that persisted even after force-stopping the YouTube app. The second time I had to restart my phone because of that I chucked the Chromecast in the trash.

Fire Stick is a joke. The wifi reception is terrible, the entire UI is laggier than my old cable box, and the apps crash on launch more often than not.

Roku just works, and it works like something that was designed by professional adults and not blood-sucking marketeers eager to screw over their users to make an extra ten cents.