Like what? I actually thought the movie was incredibly true to the book. They left out some things, sure, but it was also a very long movie and they had to trim fat.
Most of what was left out (in my opinion and observation) was the internal monologue of Katniss. That was left out because of its medium, or some things were changed. Like, when she gets a gift from Haymitch, there's a note attached. In the book she had to struggle to figure out what message he was trying to send her, and what she should do to get more gifts and/or stay alive. Again, it was changed because that wouldn't work in film.
But I'm honestly curious of what you thing was left out that should've been in.
