For starters, most people have headphones anyways since a majority of people have either a portable music player of some sort. The headphones are free on the flight but not as comfortable as the ones they are selling.

But I'll do a comparison between the last two airlines i flew (Jetblue and Northwest). I guess i would rather be nickle and dimed by B6 any day of the week.

Snacks

B6= free and unlimited plus a decent variety
NW= 2 to 5 dollars for some snack packs

Drinks

non alcoholic drinks are free on both airlines

Entertainment
B6- direct tv, xm radio, movies (free on my JFK-CUN flight)
NW - not much but there is a magazine to read on regular domestic flights

Seat Pitch

B6- 34" and higher now with fees for the extended leg room
NW- 31" and 10 dollar fee for exit row seats which are equal to a regular seat on B6