Rodney Decker describes his forthcoming elementary Greek grammar--Learning Koine Greek--as a combination of Goetchius and Mounce with up to date discussion of middle voice, verbal aspect, etc. He also says it will have "a heavy emphasis on reading actual Greek texts from the very beginning" (NT, LXX, Pseudepigrapha, and Apostolic Fathers). I really like the sound of that! Mounce's grammar is known for its reader friendly presentation. Clayton Croy's grammar includes many translation exercises from the NT and LXX. Though Goetchius' is a little older, it has a more robust linguistic framework than most elementary grammars. Decker is active in the most recent discussions of Greek grammar, and he has a keen ability to communicate clearly. If anyone can pull together the best of our current elementary grammars and improve upon them with a level-headed implementation of recent research, it is Rodney Decker. Keep an eye out for more information about this resource.