Some third-party items do qualify for Prime, if they are fulfilled by Amazon. For those of you getting late deliveries, have you contacted Amazon? You should get a free month of Prime every time that happens. None of mine have been late so far, but I just signed up in December.
Amazon just added a bunch of HBO series to Prime Video. They also have the original 24 episodes and last year's Hannibal. Current episodes will probably be up in a few months.
I just bought a Kindle so am getting lots of use out of Prime. I've got a supply of coins from that and their promos last month, so am buying apps. The new music plan is great, I've also bought a bunch of 99 cent classical albums (100 best of X type) so have lots to listen to.