I store mine on the DVD they came on. Doesn't take up that much space for a couple hundred movies. Pull the ones I want to watch when in the toyhauler and I'm good.
And I don't believe in pirating or copying movies I don't own, so that really limits what is available online.
And AFATG there really aren't that many movies I care to watch more than once other than a lot of old classics. Most modern movies cater to the younger, sophomoric crowd and I usually can't stand to watch them once, and sometimes can't even finish them. But that's just me.