We have switched mid-year to the Rod and Staff curriculum.
"Rod and Staff English is a unique blend of grammar and composition (writing) that produces outstanding results. Add Spelling by Sound and Structure to build word power, and Rod and Staff's reading (literature) to complete a thorough Language Arts Program."
I'm very pleased with this curriculum. It is biblically sound, and very thorough in its teaching. The approach is excellent as well. I have found that my 4th grader has been able to remember what she has learned with this series. For example from her English book, when I ask her to tell me what a verb phrase is, or even a verb, she is able to. She understands and remembers what it is and how to use it. That is of course the goal but I didn't find we were reaching it before trying this curriculum. A frequent reminder was needed, which was indicative that she hadn't really learned it enough to remember it. So I'm very happy with this, you can see why.
You can find it at http://www.milestonebooks.com/list/Building_Christian_English_Series/
There is also a curriculum I have read about, but never tried it. It is called Character Quality Language Arts. It encompasses all aspects of the language arts as well. You can try it for a whole month with a free download sample from their website.