I liked MGMAT SC Guide very much. You also get access to 6 online MGMAT CATs with it, one of the bests out there. It is specifically designed for gmat, so don't expect it to be like a any other high school grammar book that will teach you parts of speech etc.
Why don't you try its sample pages at Amazon.
Here you go : http://www.amazon.com/Sentence-Correction-Strategy-Edition-Manhattan/dp/1935707671
Why don't you try its sample pages at Amazon.
Here you go : http://www.amazon.com/Sentence-Correction-Strategy-Edition-Manhattan/dp/1935707671