I have had Amazon Prime now for a couple of years. I originally got their 30 day free trial near Christmas so that I could do all of my Christmas shopping and gift giving with free shipping. My intent was to ditch it after the free trial period was over.
However, I have to say that I got really spoiled with two day "no cost" shipping. Yes, I pay the annual 79 dollar fee, but I know I would do more than that in normal shipping. In addition, now that my shipping is covered, I find myself going to Amazon more. Why bother running out to the store to pick up item X when Amazon can have it to me in two days... all those little trips out prevented, add up.
I know you get the Amazon version of Netflix included... but since I have Netflix, I rarely use it. You also get the Kindle library... but since I have never had a Kindle, this was moot. However, I am getting my first Kindle next week... so I'll update with how that goes.
For me, it is mostly about the shipping... easy ordering, no going to crowded stores. Presents shipped directly to recipients. Classroom stuff sent right to my school. Easy!
So, if you have not done Amazon Prime before, at least do yourself the favor of getting it free for 30 days with Christmas around the corner... but don't be surprised if you keep it.