Prime has very few shows that Netflix doesn't. I was already a Prime member so finding out that I could stream via XBOX was icing on the cake. It's good for old kids shows or watching a series that's been off the air for a couple years, but don't expect too many current shows (or recent seasons of current shows, at least)
Netflix on the flip side, has Breaking Bad, Walking Dead, et al. But hey, considering you pay 79 bucks for the whole year with prime, get the prime video service, prime book renting (1 per week i believe) VIA kindle and free 2 day shipping on amazon's website, that's bloody hard to beat.