Whichever you're most popular on, they all have their merits. Facebook is usually people you actually know and they tend to give more support, but twitter can be used to add/remove for followers so you can slowly build up followers that don't actually know you and then drop a video link one day for attention. I think the best bet is to do all of it, if possible.
I'd say Twitter is the best, then Instagram, then Facebook. Facebook pages posts rarely reach all the people who've liked the page, though Twitter has more reach and hashtags help even more people see your tweets . Twitter is also better to interact with your viewers.