I've been using Barsam's book for several years now in my film class, having chosen it to replace Giannetti's "Understanding Movies," and before that, Bordwell/Thompson's "Film Art: An Introduction." My current students like it and so do I (and my students who have used Giannetti's text and Pramaggiore's "Film: A Critical Introduction" in other classes say they prefer the Barsam to both of those).
Barsam covers all the requisite formal elements (narrative, cinematography, mise-en-scene, acting, editing, etc.), usually devoting a chapter to each topic--as do almost all film books of this type. But Barsam's book is better organized than most. Giannetti, by contrast, has a entire chapter on movement, whereas Barsam handles camera movement in his cinematography chapter and movement within the image in his chapter on mise-en-scene--which I think makes much more sense. And Barsam strikes a nice balance between academic rigor and accessibility (I stopped using the Bordwell/Thompson, which is often considered the standard, because undergraduate students found the tone too scholarly and the discussions too obtuse). The new 3rd edition of "Looking at Movies" adds a valuable and much-needed chapter on film history and expands the discussion of film technology, production and marketing. And of course, Barsam's book (like most others) is copiously illustrated, with helpful captions (and the layout and design is better in Barsam's than in most other texts of this sort). The writing is engaging, readable and informative. In short, a great text.
The new edition does have a few weaknesses, however--at least, in my opinion. Firstly, the book now takes an awfully long time to get going: Barsam has added and re-arranged material into three long wind-up chapters introducing film appreciation, film forms and film types. The better solution--I think--would have been simply to revise the old material and include the new material (as well as some of the original material) in other other chapters where it topically belongs (moving the discussion of genres, for example, into the chapter on narrative). As is, the reader (or teacher and student) either has to wade through all that preliminary discussion prior to getting to the really meaty material, or she has to jump around in the book and split up the reading so as to address everything that is topically related in one read. Secondly, Barsam now pays almost no attention at all to film theory and theorists, even in the film history chapter (Giannetti, by contrast, has an entire chapter on theory, while other authors cover theory piecemeal throughout their respective texts). The 2nd edition had an entire chapter on film theory and criticism. It was admittedly a bit clunky, but the better solution would have been to rewrite it, not remove it entirely--which leaves a gaping hole in what is otherwise admirable coverage of all the important topics. Lastly, Barsam has a quirky understanding of mise-en-scene, broadening the concept so much that it becomes almost synonymous with the movie per se, rather than restricting mise-en-scene to a focus on the image and its composition and constituent components--although, to his credit, Barsam admits as much to the reader and then proceeds to handle his actual analyses much as everyone else does.
It is possible to buy the text bundled with a small booklet on writing about movies (which is a pretty good treatment) and a truly excellent dvd with film shorts and some of the best tutorials (by David Monahan) available anywhere. The dvd alone is almost worth the purchase price of the book, and is an invaluable student resource.
All things considered, then, (despite the puzzling loss of the theory chapter), Barsam's "Looking at Movies" is the best all-around choice for an introduction to film text, and I highly recommend it.