Explode The Code (ETC) is so great. We started on 6 or 7 and have been steadily working through the series. I wish I had found these way earlier.
ETC is not super colorful, but it's not too drab either. It gives several ways to learn per 'section' like...read a page then answer questions, fill in's, games etc. It's not like those super big books you can get at walmart but it's great for grammar, spelling, rules...we love these. Try one out, great for homeschool or catch up for kids having troubles.