then any of those would be fine.
However, if the movies you plan on watching are on DVD then the MBP wold be the better option as it has a DVD player built in, the Air does not. (There is an available, external, DVD option for it though)
If these movies are going to be files, not a physical DVD, then bear in mind that the Air has a relatively small SSD drive (256GB)
A bunch of movies and a good size iTunes library could quickly eat up 256GB.
Your local Apple Store will be able to supply any of the three machines that you have mentioned.
Hi, I need help to decide which MacBook to get, or which one is better, I use it mostly to view movies, surf the web and use itunes.
My decision has come between:
A MacBook Air 2.0GHz Intel Dual-Core Core i7, Turbo Boost up to 3.2GHz 4GB 1600MHz DDR3L SDRAM
256GB Flash Storage
...(not sure if they have this one at my Apple Store, if not it will be MBA 1.8GHz Intel Dual-Core Core i5, Turbo Boost up to 2.8GHz 4GB 1600MHz DDR3L SDRAM
256GB Flash Storage)
and a MacBook Pro 2.9GHz Dual-core Intel Core i7, Turbo Boost up to 3.6GHz
8GB 1600MHz DDR3 SDRAM — 2x4GB 750GB Drive