We use Netflix and Amazon Prime. We don't have cable.
A few years ago we tried the free trial period of Hulu Plus, but there were a ton of glitches, wheels kept spinning. We almost never have that problem with Netflix. Plus, I found that the few shows I liked to watch that were current weren't even available on Hulu Plus. This all may have changed.
Netflix is awesome for the kids, which is what we usually use it for. Plus, since we are so busy, we tend to be seasons behind on shows, so it works for us. We watched all of Breaking Bad on Netflix, and I'm now watching House of Cards.
Amazon Prime is what we use for all Nickelodeon shows. Netflix used to carry them, but they don't anymore. We can get at least the first one or two seasons of Dora, Blue's Clues, Yo Gabba, etc. with Amazon Prime. I also use their on-demand exercise videos. Netflix doesn't have any.
I've also discovered that if there is something I really want to watch on network TV, I can find it on YouTube. We can stream YouTube to our TV, so that works well too.