Here's a quick rundown of all the places to eat on campus, based entirely on my opinions and tastes in food (so, grain of salt and all that jazz).
Campus food is generally good, though the different places vary. The best place to eat on campus is in Woodworth. They have the best salads (made to order and spun in front of you), plus they rotate Asian and Mexican food, both of which are made to order and very good. It just opened last year, so everything is new-- the seating is comfortable and fresh, and the lines flow quickly and easily. However, since it really is so delicious, it tends to be crowded around mealtimes, so I suggest eating a little before or a little after the12:00-1:00 and the 6:00-7:00 rush, unless the crowds don't bother you.
The library's Bookmark Cafe is one of my favorite places to eat-- I like their Chai tea and their soup selections, which are very satisfying on cold winter days. They also have a nice pastry selection, which can help make long hours of studying more bearable. My suggestion? Get some tomato basil soup and some cheese cubes, then put the cubes in the soup to let them get all soft and melty. . . yummmmmmmmmmmmm. :)
I also eat many meals at Noyer. They have a salad bar and made-to-order wraps and subs. I'm a huge fan of the salad bar in particular-- you can pile on the kidney beans (yum!) and leave out the carrots (ick!). They also have a place called "Mom's," and it usually has typical Mid-western foods like meat and mashed potatoes, and it's usually good. The real jewel of Noyer is the International Cafe, which has a menu that rotates every semester (it seems), so every day of the semester has something different, ranging from brats to streak. If you can be there on the right day, they have this eggplant grilled sandwich to die for. Actually, I like everything in Noyer Center except the hamburgers, which taste like what you might expect from a gas station. If you're in a hurry they're fine, but otherwise Noyer has more to offer.
Noyer also has one of the campus's buffets, called The Retreat. During the day it's reserved for professors and staff, but it's open to students in the evenings. It works like a normal buffet: you pay one price for as much food as you care to eat. The menu changes daily, and it's posted outside the entrance so you can make your decision before you pay. It's always been good when I've gone, plus they tend to host special meals for holidays, including a Thanksgiving Feast and Cajun food for Mardi Gras.
If you're looking for fast food, the Atrium has Chick-Fil-A and Sbarro. If you're looking for a GREAT hamburger, go to the Atrium. They have bread bowls for soup, which again are really nice on cold days.
The Student Center just opened this year, and it has Taco Bell. Enough said. (For the record, I could eat Taco Bell most days of the week.) :)
The remaining places to eat are Elliot Dining, which I've never been to (but I think it's a buffet), and LaFollette, which boasts really good sandwiches and a great breakfast buffet, but little else. In my experience, you won't really eat at either of these places unless you live near them and it's convenient. I lived near LaFollette for three years, so I ate there a lot; however, Elliot is literally on the opposite side of campus and not really near any buildings I have class in, so to date I've never been there. Neither one is considered students' favorites, but sometimes they can be nice for a change of pace.
If you're still curious about Ball State dining, I highly recommend coming for a campus tour. When I toured as a prospective freshwoman, Ball State gave my family dining credit so we could all try Ball State cuisine for ourselves. Your tour guide might end the tour in the Atrium, but you'll be free to try food wherever you want. I suggest going to Noyer or Woodworth; if in doubt, ask your guide for directions to his or her favorite place to eat on campus.