I went with a 64GB and have only about 9GB available now, that's after putting all of my music, photos, 30 TV shows, and 14 movies. Pretty good if you ask me lol.
I bought the 16GB version only because my music library is 145GB. My choice is have some of my library missing, or a lot of my library missing. However, Simplify Media on my iPhone works damn well so I have all my tunes wherever i go.. I'm having no regrets, and I'm glad they didn't cripple the 16GB hardware specs to push folks to a pricier model.