Only things I've tried so far are Amazon Prime (works reasonably well with Dolphin Browser but not perfect), and an app called Full Classic Movies (or something like that) which links to old films on You Tube. Worked pretty well.
Only other one I've tried is Crackle TV, but don't remember how well it worked.
I chalked up the less than perfect performance with Amazon to my wireless access which is an Apple Airport Express. Works great and hasn't missed a beat since I installed it in March. Just not up to the speeds needed for Amazon I guess.
But anyway, yeah I'd like to watch movies too, but it's not a must for me.
I have a really decent A/V system, full 7.1 audio, two subs, great display, so that'where I do my movie watching.
But there are times when watching something on the tab is fun too.
What are your movie interests? I occassionally look for movie sites, might find something.