It really depends on what you are looking for.
If you want Italian, then I would say 1) Venezia's 2) Italian Village or 3) The Garlic Press (in that order).
NOTE: That is unless you can catch a wine dinner that the Garlic Press holds in conjunction with Pinkie's. I haven't attended one since the Wine Rack quit sponsoring the dinners, but they were fantastic then. The only problem is that they do them on a Monday.
If you want Chinese, then I would say your only choice is Kuo's. My wife and I enjoy their food.
If you are looking for a steak, then Wall Street is really the only option. As was also mentioned, the Barn Door is good if you want to drive to Odessa.
If you want Mexican food, then start with Gerardo's and keep going from there. There are several up and down Big Spring, and they are all pretty good. Abuelo's is also good as another poster mentioned above.
Miscellaneous: I haven't tried Osaka but I hear they are good as well. Also Clear Springs is good if you want onion rings and beer.
Good luck and I hope she enjoys Midland.